Public-domain books

The First Steps in Algebra

Multiplication and Division

Excerpts

Equations

Problems

Exercise 21

  1. Exercise 21, problem 1, p. 53

    $x + 7$ and $x$.

    Printed answer:
    • $x^{2} + 7x$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**2 + 7*x
  2. Exercise 21, problem 10, p. 53

    $2 x^{3} - 3x^{2}$ and $2x^{2}$.

    Printed answer:
    • $4x^{5} - 6x^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 4*x**5 - 6*x**4
  3. Exercise 21, problem 11, p. 53

    $x^{2} - 3y^{2}$ and $4y$.

    Printed answer:
    • $4x^{2}y - 12y^{3}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 4*x**2*y - 12*y**3
  4. Exercise 21, problem 12, p. 53

    $x^{2} - 3 y^{2}$ and $-x^{2}$.

    Printed answer:
    • $-x^{4} + 3x^{2}y^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -x**4 + 3*x**2*y**2
  5. Exercise 21, problem 13, p. 53

    $b^{3} - a^{2}b^{2}$ and $-a^{3}$.

    Printed answer:
    • $-a^{3}b^{3} + a^{5}b^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -a**3*b**3 + a**5*b**2
  6. Exercise 21, problem 14, p. 53

    $-a^{2}b^{2} - a^{3}$ and $-a^{2}$.

    Printed answer:
    • $a^{4}b^{2} + a^{5}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**4*b**2 + a**5
  7. Exercise 21, problem 15, p. 53

    $2x^{3} - 3x^{2} + x$ and $2x^{2}$.

    Printed answer:
    • $4x^{5} - 6x^{4} + 2x^{3}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 4*x**5 - 6*x**4 + 2*x**3
  8. Exercise 21, problem 16, p. 53

    $a^{2} - 5ab - b^{2}$ and $5ab$.

    Printed answer:
    • $5a^{3}b - 25a^{2}b^{2} - 5ab^{3}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 5*a**3*b - 25*a**2*b**2 - 5*a*b**3
  9. Exercise 21, problem 17, p. 53

    $a^{3} + 2a^{2}b + 2ab^{2}$ and $a^{2}$.

    Printed answer:
    • $a^{5} + 2a^{4}b + 2a^{3}b^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**5 + 2*a**4*b + 2*a**3*b**2
  10. Exercise 21, problem 18, p. 53

    $a^{3} + 2a^{2}b + 2ab^{2}$ and $b^{3}$.

    Printed answer:
    • $a^{3}b^{3} + 2a^{2}b^{4} + 2ab^{5}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**3*b**3 + 2*a**2*b**4 + 2*a*b**5
  11. Exercise 21, problem 19, p. 53

    $4x^{2} - 6xy - 9y^{2}$ and $2x$.

    Printed answer:
    • $8x^{3} - 12x^{2}y - 18xy^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 8*x**3 - 12*x**2*y - 18*x*y**2
  12. Exercise 21, problem 2, p. 53

    $2x - 3y$ and $4x$.

    Printed answer:
    • $8x^{2} - 12xy$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 8*x**2 - 12*x*y
  13. Exercise 21, problem 20, p. 53

    $-x^{2} - 2xy + y^{2}$ and $-y$.

    Printed answer:
    • $x^{2}y + 2xy^{2} - y^{3}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**2*y + 2*x*y**2 - y**3
  14. Exercise 21, problem 21, p. 53

    $-a^{3} - a^{2}b^{2} - b^{3}$ and $-a^{2}$.

    Printed answer:
    • $a^{5} + a^{4}b^{2} + a^{2}b^{3}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**5 + a**4*b**2 + a**2*b**3
  15. Exercise 21, problem 22, p. 53

    $-x^{2} + 2xy - y^{2}$ and $-y^{2}$.

    Printed answer:
    • $x^{2}y^{2} - 2xy^{3} + y^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**2*y**2 - 2*x*y**3 + y**4
  16. Exercise 21, problem 23, p. 53

    $3 a^{2}b^{2} - 4 ab^{3} + a^{3}b$ and $5 a^{2}b^{2}$.

    Printed answer:
    • $15a^{4}b^{4} - 20a^{3}b^{5} + 5a^{5}b^{3}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 15*a**4*b**4 - 20*a**3*b**5 + 5*a**5*b**3
  17. Exercise 21, problem 24, p. 53

    $-ax^{2} + 3axy^{2} - ay^{4}$ and $-3ay^{2}$.

    Printed answer:
    • $3a^{2}x^{2}y^{2} - 9a^{2}xy^{4} + 3a^{2}y^{6}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 3*a**2*x**2*y**2 - 9*a**2*x*y**4 + 3*a**2*y**6
  18. Exercise 21, problem 25, p. 53

    $x^{12} - x^{10}y^{3} - x^{3}y^{10}$ and $x^{3}y^{2}$.

    Printed answer:
    • $x^{15}y^{2} - x^{13}y^{5} - x^{6}y^{12}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**15*y**2 - x**13*y**5 - x**6*y**12
  19. Exercise 21, problem 26, p. 53

    $-2x^{3} + 3x^{2}y^{2} - 2xy^{3}$ and $-2x^{2}y^{3}$.

    Printed answer:
    • $4x^{5}y^{3} - 6x^{4}y^{5} + 4x^{3}y^{6}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 4*x**5*y**3 - 6*x**4*y**5 + 4*x**3*y**6
  20. Exercise 21, problem 27, p. 53

    $a^{3}x^{2}y^{5} - a^{2}xy^{4} - ay^{3}$ and $a^{7}x^{3}y^{5}$.

    Printed answer:
    • $a^{10}x^{5}y^{10} - a^{9}x^{4}y^{9} - a^{8}x^{3}y^{8}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**10*x**5*y**10 - a**9*x**4*y**9 - a**8*x**3*y**8
  21. Exercise 21, problem 28, p. 53

    $3a^{2}b^{2} - 2ab^{3} + 5a^{3}b$ and $5a^{2}b^{3}$.

    Printed answer:
    • $15a^{4}b^{5} - 10a^{3}b^{6} + 25a^{5}b^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 15*a**4*b**5 - 10*a**3*b**6 + 25*a**5*b**4
  22. Exercise 21, problem 3, p. 53

    $2x - 3y$ and $7y$.

    Printed answer:
    • $14xy - 21y^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 14*x*y - 21*y**2
  23. Exercise 21, problem 4, p. 53

    $x - 2a$ and $2a$.

    Printed answer:
    • $2ax - 4a^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 2*a*x - 4*a**2
  24. Exercise 21, problem 5, p. 53

    $-x + 3b$ and $-b$.

    Printed answer:
    • $bx - 3b^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes b*x - 3*b**2
  25. Exercise 21, problem 6, p. 53

    $2a^{2} - 3ab$ and $-3a$.

    Printed answer:
    • $-6a^{3} + 9a^{2}b$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -6*a**3 + 9*a**2*b
  26. Exercise 21, problem 7, p. 53

    $2x^{2} + 3xz$ and $5z$.

    Printed answer:
    • $10x^{2}z + 15xz^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 10*x**2*z + 15*x*z**2
  27. Exercise 21, problem 8, p. 53

    $a^{2} - 5ab$ and $5ab$.

    Printed answer:
    • $5a^{3}b - 25a^{2}b^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 5*a**3*b - 25*a**2*b**2
  28. Exercise 21, problem 9, p. 53

    $x^{2} - 3 xy$ and $-y^{2}$.

    Printed answer:
    • $-x^{2}y^{2} + 3xy^{3}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -x**2*y**2 + 3*x*y**3

Exercise 22

  1. Exercise 22, problem 1, p. 56

    $x + 7$ and $x + 6$.

    Printed answer:
    • $x^{2} + 13x + 42$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**2 + 13*x + 42
  2. Exercise 22, problem 10, p. 56

    $5x - 3$ and $4x - 7$.

    Printed answer:
    • $20x^{2} - 47x + 21$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 20*x**2 - 47*x + 21
  3. Exercise 22, problem 11, p. 56

    $a - 2b$ and $a + 3b$.

    Printed answer:
    • $a^{2} + ab - 6b^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**2 + a*b - 6*b**2
  4. Exercise 22, problem 12, p. 56

    $a - 7b$ and $a - 5b$.

    Printed answer:
    • $a^{2} - 12ab + 35b^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**2 - 12*a*b + 35*b**2
  5. Exercise 22, problem 13, p. 56

    $5x - 3y$ and $5x - 3y$.

    Printed answer:
    • $25x^{2} - 30xy + 9y^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 25*x**2 - 30*x*y + 9*y**2
  6. Exercise 22, problem 14, p. 56

    $x - b$ and $x - c$.

    Printed answer:
    • $x^{2} - bx - cx + bc$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**2 - b*x - c*x + b*c
  7. Exercise 22, problem 15, p. 56

    $2m - p$ and $4m - 3p$.

    Printed answer:
    • $8m^{2} - 10mp + 3p^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 8*m**2 - 10*m*p + 3*p**2
  8. Exercise 22, problem 16, p. 56

    $a + b + c$ and $a - c$.

    Printed answer:
    • $a^{2} + ab - bc - c^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**2 + a*b - b*c - c**2
  9. Exercise 22, problem 17, p. 56

    $a^{2} - ab + b^{2}$ and $a^{2} + b^{2}$.

    Printed answer:
    • $a^{4} - a^{3}b + 2a^{2}b^{2} - ab^{3} + b^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**4 - a**3*b + 2*a**2*b**2 - a*b**3 + b**4
  10. Exercise 22, problem 18, p. 56

    $x^{3} - 3x^{2} + 7$ and $x^{2} - 3$.

    Printed answer:
    • $x^{5} - 3x^{4} - x^{3} + 16x^{2} - 21$.

    unverified: no computed check settled this one (yet)

    How it was checked
    • identity: the printed answer does not match the problem x**5 - 3*x**4 - x**3 + 16*x**2 - 21
  11. Exercise 22, problem 19, p. 56

    $a^{2} + ab + b^{2}$ and $a - b$.

    Printed answer:
    • $a^{3} - b^{3}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**3 - b**3
  12. Exercise 22, problem 2, p. 56

    $x - 7$ and $x + 6$.

    Printed answer:
    • $x^{2} - x - 42$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**2 - x - 42
  13. Exercise 22, problem 20, p. 56

    $a^{2} - ab + b^{2}$ and $a + b$.

    Printed answer:
    • $a^{3} + b^{3}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**3 + b**3
  14. Exercise 22, problem 21, p. 56

    $x^{2} + 5x - 10$ and $2x^{2} + 3x - 4$.

    Printed answer:
    • $2x^{4} + 13x^{3} - 9x^{2} - 50x + 40$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 2*x**4 + 13*x**3 - 9*x**2 - 50*x + 40
  15. Exercise 22, problem 22, p. 56

    $3x^{3} - 2x^{2} + x$ and $3x^{2} + 2x - 2$.

    Printed answer:
    • $9x^{5} - 7x^{3} + 6x^{2} - 2x$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 9*x**5 - 7*x**3 + 6*x**2 - 2*x
  16. Exercise 22, problem 23, p. 56

    $x^{3} + 2x^{2}y + 3xy^{2}$ and $x^{2} - 2xy + y^{2}$.

    Printed answer:
    • $x^{5} - 4x^{2}y^{3} + 3xy^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**5 - 4*x**2*y**3 + 3*x*y**4
  17. Exercise 22, problem 24, p. 56

    $a^{2} - 3ab - b^{2}$ and $-a^{2} + ab + 2b^{2}$.

    Printed answer:
    • $-a^{4} + 4a^{3}b - 7ab^{3} - 2b^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -a**4 + 4*a**3*b - 7*a*b**3 - 2*b**4
  18. Exercise 22, problem 25, p. 56

    $3a^{2}b^{2} + 2 ab^{3} - 5a^{3}b$ and $5a^{2}b^{2} - ab^{3} - b^{4}$.

    Printed answer:
    • $-25a^{5}b^{3} + 20a^{4}b^{4} + 12a^{3}b^{5} - 5a^{2}b^{6} - 2ab^{7}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -25*a**5*b**3 + 20*a**4*b**4 + 12*a**3*b**5 - 5*a**2*b**6 - 2*a*b**7
  19. Exercise 22, problem 26, p. 56

    $a^{2} - 2ab + b^{2}$ and $a^{2} + 2ab + b^{2}$.

    Printed answer:
    • $a^{4} - 2a^{2}b^{2} + b^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**4 - 2*a**2*b**2 + b**4
  20. Exercise 22, problem 27, p. 56

    $ab + ac + cd$ and $ab - ac + cd$.

    Printed answer:
    • $a^{2}b^{2} + 2abcd - a^{2}c^{2} + c^{2}d^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**2*b**2 + 2*a*b*c*d - a**2*c**2 + c**2*d**2
  21. Exercise 22, problem 28, p. 56

    $3x^{2}y^{2} + xy^{3} - 2x^{3}y$ and $x^{2}y^{2} + xy^{3} - 3y^{4}$.

    Printed answer:
    • $-2x^{5}y^{3} + x^{4}y^{4} + 10x^{3}y^{5} - 8x^{2}y^{6} - 3xy^{7}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -2*x**5*y**3 + x**4*y**4 + 10*x**3*y**5 - 8*x**2*y**6 - 3*x*y**7
  22. Exercise 22, problem 29, p. 56

    $x^{2} + 2xy - y^{2}$ and $x^{2} - 2xy + y^{2}$.

    Printed answer:
    • $x^{4} - 4x^{2}y^{2} + 4xy^{3} - y^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**4 - 4*x**2*y**2 + 4*x*y**3 - y**4
  23. Exercise 22, problem 3, p. 56

    $x + 7$ and $x - 6$.

    Printed answer:
    • $x^{2} + x - 42$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**2 + x - 42
  24. Exercise 22, problem 30, p. 56

    $3x^{2} + xy - y^{2}$ and $x^{2} - 2xy - 3y^{2}$.

    Printed answer:
    • $3x^{4} - 5x^{3}y - 12x^{2}y^{2} - xy^{3} + 3y^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 3*x**4 - 5*x**3*y - 12*x**2*y**2 - x*y**3 + 3*y**4
  25. Exercise 22, problem 31, p. 56

    $a^{2} - 2ab - b^{2}$ and $b^{2} - 2ab - a^{2}$.

    Printed answer:
    • $-a^{4} + 6a^{2}b^{2} - b^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -a**4 + 6*a**2*b**2 - b**4
  26. Exercise 22, problem 32, p. 56

    $a^{2} + b^{2} + c^{2} - ac$ and $a^{2} - b^{2} - c^{2}$.

    Printed answer:
    • $a^{4} - a^{3}c + ab^{2}c - b^{4} - 2b^{2}c^{2} + ac^{3} - c^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**4 - a**3*c + a*b**2*c - b**4 - 2*b**2*c**2 + a*c**3 - c**4
  27. Exercise 22, problem 33, p. 56

    $a^{2} + 4abx - 4a^{2}b^{2}x^{2}$ and $a^{2} - 4abx + 4a^{2}b^{2}x^{2}$.

    Printed answer:
    • $a^{4} - 16a^{2}b^{2}x^{2} + 32a^{3}b^{3}x^{3} - 16a^{4}b^{4}x^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**4 - 16*a**2*b**2*x**2 + 32*a**3*b**3*x**3 - 16*a**4*b**4*x**4
  28. Exercise 22, problem 34, p. 56

    $3 a^{2} - 2abx + b^{2}x^{2}$ and $2a^{2} + 3abx - 2b^{2}x^{2}$.

    Printed answer:
    • $6a^{4} + 5a^{3}bx - 10a^{2}b^{2}x^{2} + 7ab^{3}x^{3} - 2b^{4}x^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 6*a**4 + 5*a**3*b*x - 10*a**2*b**2*x**2 + 7*a*b**3*x**3 - 2*b**4*x**4
  29. Exercise 22, problem 35, p. 56

    $2x^{3}y + 4x^{2}y^{2} - 8xy^{3}$ and $2xy^{3} - 3x^{2}y^{2} + 5x^{3}y$.

    Printed answer:
    • $10x^{6}y^{2} + 14x^{5}y^{3} - 48x^{4}y^{4} + 32x^{3}y^{5} - 16x^{2}y^{6}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 10*x**6*y**2 + 14*x**5*y**3 - 48*x**4*y**4 + 32*x**3*y**5 - 16*x**2*y**6
  30. Exercise 22, problem 4, p. 56

    $x - 7$ and $x - 6$.

    Printed answer:
    • $x^{2} - 13x + 42$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**2 - 13*x + 42
  31. Exercise 22, problem 5, p. 56

    $x + 8$ and $x - 5$.

    Printed answer:
    • $x^{2} + 3x - 40$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**2 + 3*x - 40
  32. Exercise 22, problem 6, p. 56

    $2x + 3$ and $2x + 3$.

    Printed answer:
    • $4x^{2} + 12x + 9$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 4*x**2 + 12*x + 9
  33. Exercise 22, problem 7, p. 56

    $2x - 3$ and $2x - 3$.

    Printed answer:
    • $4x^{2} - 12x + 9$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 4*x**2 - 12*x + 9
  34. Exercise 22, problem 8, p. 56

    $2x + 3$ and $2x - 3$.

    Printed answer:
    • $4x^{2} - 9$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 4*x**2 - 9
  35. Exercise 22, problem 9, p. 56

    $3x - 2$ and $2 - 3x$.

    Printed answer:
    • $-9x^{2} + 12x - 4$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -9*x**2 + 12*x - 4

Exercise 23

  1. Exercise 23, problem 1, p. 58

    $2a^{3} - a^{2}$ by $a$.

    Printed answer:
    • $2a^{2} - a$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 2*a**2 - a
  2. Exercise 23, problem 10, p. 58

    $-5x^{3} + x^{2}y$ by $-x^{2}$.

    Printed answer:
    • $5x - y$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 5*x - y
  3. Exercise 23, problem 11, p. 58

    $2a^{5}x^{3} - 2a^{4}x^{2}$ by $2a^{4}x^{2}$.

    Printed answer:
    • $ax - 1$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a*x - 1
  4. Exercise 23, problem 12, p. 58

    $-x^{2}y - x^{2}y^{2}$ by $-xy$.

    Printed answer:
    • $x + xy$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x + x*y
  5. Exercise 23, problem 13, p. 58

    $9a - 12b + 6c$ by $-3$.

    Printed answer:
    • $-3a + 4b - 2c$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -3*a + 4*b - 2*c
  6. Exercise 23, problem 14, p. 58

    $a^{3}b^{2} - a^{2}b^{5} - a^{4}b^{2}$ by $a^{2}b$.

    Printed answer:
    • $ab - b^{4} - a^{2}b$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a*b - b**4 - a**2*b
  7. Exercise 23, problem 15, p. 58

    $3x^{3} - 6x^{2}y - 9xy^{2}$ by $3x$.

    Printed answer:
    • $x^{2} - 2xy - 3y^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**2 - 2*x*y - 3*y**2
  8. Exercise 23, problem 16, p. 58

    $x^{2}y^{2} - x^{3}y - xy^{3}$ by $xy$.

    Printed answer:
    • $xy - x^{2} - y^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x*y - x**2 - y**2
  9. Exercise 23, problem 17, p. 58

    $a^{3} - a^{2}b - ab^{2}$ by $-a$.

    Printed answer:
    • $-a^{2} + ab + b^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -a**2 + a*b + b**2
  10. Exercise 23, problem 18, p. 58

    $a^{2}b - ab + ab^{2}$ by $-ab$.

    Printed answer:
    • $-a + 1 - b$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -a + 1 - b
  11. Exercise 23, problem 19, p. 58

    $xy - x^{2}y^{2} + x^{3}y^{3}$ by $-xy$.

    Printed answer:
    • $-1 + xy - x^{2}y^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -1 + x*y - x**2*y**2
  12. Exercise 23, problem 2, p. 58

    $42a^{5} - 6a^{2}$ by $6a$.

    Printed answer:
    • $7a^{4} - a$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 7*a**4 - a
  13. Exercise 23, problem 20, p. 58

    $-x^{6} - 2x^{5} - x^{4}$ by $-x^{4}$.

    Printed answer:
    • $x^{2} + 2x + 1$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**2 + 2*x + 1
  14. Exercise 23, problem 21, p. 58

    $a^{2}x - abx - acx$ by $ax$.

    Printed answer:
    • $a - b - c$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a - b - c
  15. Exercise 23, problem 22, p. 58

    $3x^{5}y^{2} - 3x^{4}y^{3} - 3x^{2}y^{4}$ by $3x^{2}y^{2}$.

    Printed answer:
    • $x^{3} - x^{2}y - y^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**3 - x**2*y - y**2
  16. Exercise 23, problem 23, p. 58

    $a^{2}b^{2} - 2ab - 3ab^{3}$ by $ab$.

    Printed answer:
    • $ab - 2 - 3b^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a*b - 2 - 3*b**2
  17. Exercise 23, problem 24, p. 58

    $3a^{3}c^{3} + 3a^{2}c - 3ac^{2}$ by $3ac$.

    Printed answer:
    • $a^{2}c^{2} + a - c$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**2*c**2 + a - c
  18. Exercise 23, problem 3, p. 58

    $21x^{4} + 3x^{2}$ by $3x^{2}$.

    Printed answer:
    • $7x^{2} + 1$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 7*x**2 + 1
  19. Exercise 23, problem 4, p. 58

    $35m^{4} - 7p^{2}$ by $7$.

    Printed answer:
    • $5m^{4} - p^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 5*m**4 - p**2
  20. Exercise 23, problem 5, p. 58

    $27x^{5} - 45x^{4}$ by $9x^{2}$.

    Printed answer:
    • $3x^{3} - 5x^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 3*x**3 - 5*x**2
  21. Exercise 23, problem 6, p. 58

    $24x^{6} - 8x^{3}$ by $-8x^{3}$.

    Printed answer:
    • $-3x^{3} + 1$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -3*x**3 + 1
  22. Exercise 23, problem 7, p. 58

    $34x^{3} - 51x^{2}$ by $17x$.

    Printed answer:
    • $2x^{2} - 3x$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 2*x**2 - 3*x
  23. Exercise 23, problem 8, p. 58

    $5x^{5} - 10x^{3}$ by $-5x^{3}$.

    Printed answer:
    • $-x^{2} + 2$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -x**2 + 2
  24. Exercise 23, problem 9, p. 58

    $-3a^{2} - 6ac$ by $-3a$.

    Printed answer:
    • $a + 2c$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a + 2*c

Exercise 24

  1. Exercise 24, problem 1, p. 62

    $x^{2} + 15x + 56$ by $x + 7$.

    Printed answer:
    • $x + 8$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x + 8
  2. Exercise 24, problem 10, p. 62

    $x^{8} + x^{4} + 1$ by $x^{4} - x^{2} + 1$.

    Printed answer:
    • $x^{4} + x^{2} + 1$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**4 + x**2 + 1
  3. Exercise 24, problem 11, p. 62

    $1 - a^{3}b^{3}$ by $1 - ab$.

    Printed answer:
    • $1 + ab + a^{2}b^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 1 + a*b + a**2*b**2
  4. Exercise 24, problem 12, p. 62

    $x^{3} - 8x-3$ by $x - 3$.

    Printed answer:
    • $x^{2} + 3x + 1$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**2 + 3*x + 1
  5. Exercise 24, problem 13, p. 62

    $a^{2} - 2ab + b^{2} - c^{2}$ by $a - b - c$.

    Printed answer:
    • $a - b + c$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a - b + c
  6. Exercise 24, problem 14, p. 62

    $a^{2} + 2ab + b^{2} - c^{2}$ by $a + b + c$.

    Printed answer:
    • $a + b - c$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a + b - c
  7. Exercise 24, problem 15, p. 62

    $x^{2} - y^{2} + 2yz - z^{2}$ by $x - y + z$.

    Printed answer:
    • $x + y - z$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x + y - z
  8. Exercise 24, problem 16, p. 62

    $c^{4} + 2c^{2} - c + 2$ by $c^{2} - c + 1$.

    Printed answer:
    • $c^{2} + c + 2$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes c**2 + c + 2
  9. Exercise 24, problem 17, p. 62

    $x^{2} - 4y^{2} - 4yz - z^{2}$ by $x + 2y + z$.

    Printed answer:
    • $x - 2y - z$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x - 2*y - z
  10. Exercise 24, problem 18, p. 62

    $x^{3} - 6a^{3} + 11a^{2}x - 6ax^{2}$ by $x^{2} + 6a^{2} - 5ax$.

    Printed answer:
    • $x - a$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x - a
  11. Exercise 24, problem 19, p. 62

    $a^{2} - 4b^{2} - 9c^{2} + 12bc$ by $a - 3c + 2b$.

    Printed answer:
    • $a - 2b + 3c$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a - 2*b + 3*c
  12. Exercise 24, problem 2, p. 62

    $x^{2} - 15x + 56$ by $x - 7$.

    Printed answer:
    • $x - 8$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x - 8
  13. Exercise 24, problem 20, p. 62

    $2a^{3} - 8a + a^{4} + 12-7a^{2}$ by $2 + a^{2} - 3a$.

    Printed answer:
    • $a^{2} + 5a + 6$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**2 + 5*a + 6
  14. Exercise 24, problem 21, p. 62

    $q^{4} + 6q^{3} + 4 + 12q + 13q^{2}$ by $3q + 2 + q^{2}$.

    Printed answer:
    • $q^{2} + 3q + 2$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes q**2 + 3*q + 2
  15. Exercise 24, problem 22, p. 62

    $27a^{3} - 8b^{3}$ by $3a - 2b$.

    Printed answer:
    • $9a^{2} + 6ab + 4b^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 9*a**2 + 6*a*b + 4*b**2
  16. Exercise 24, problem 23, p. 62

    $a^{4} + 9a^{2} + 15-11a - 7a^{3}$ is divided by $a - 5$.

    Printed answer:
    • $-65$.

    verified: the printed answer passed a computed check

    How it was checked
    • evaluate: passes -65

    On the STU-32 (STU, rpn):

    5 ENTER 7 −
    5 × 9 +
    5 × 11 −
    5 × 15 +

    Calculator: -65E+0; the book prints -65. Run on the calculator core at firmware 628c96c.

  17. Exercise 24, problem 24, p. 62

    $7 - 8c^{2} + 5c^{3} + 8c$ is divided by $5c - 3$.

    Printed answer:
    • $10$.

    verified: the printed answer passed a computed check

    How it was checked
    • evaluate: passes 10

    On the STU-32 (STU, rpn):

    3 ENTER 5 ÷ ENTER ENTER ENTER 5 ×
    8 −
    ×
    8 +
    ×
    7 +

    Calculator: +10000E-3; the book prints 10. Run on the calculator core at firmware 628c96c.

  18. Exercise 24, problem 25, p. 62

    $3 + 11a^{3} + 30a^{4} - 82a^{2} - 5a$ is divided by $3a^{2} - 4 + 2a$.

    Printed answer:
    • $7a - 45$.

    unverified: no computed check settled this one (yet)

    How it was checked
    • other: not a kind the checker handles 7*a - 45
  19. Exercise 24, problem 26, p. 62

    $2x^{3} - 16x + 10-39x^{2} + 17x^{4}$ is divided by $2 - 5x^{2} - 4x$.

    Printed answer:
    • $2x^{4}$.

    unverified: no computed check settled this one (yet)

    How it was checked
    • other: not a kind the checker handles 2*x**4
  20. Exercise 24, problem 3, p. 62

    $x^{2} + x-56$ by $x - 7$.

    Printed answer:
    • $x + 8$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x + 8
  21. Exercise 24, problem 4, p. 62

    $x^{2} - x-56$ by $x + 7$.

    Printed answer:
    • $x - 8$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x - 8
  22. Exercise 24, problem 5, p. 62

    $2a^{2} + 11a + 5$ by $2a + 1$.

    Printed answer:
    • $a + 5$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a + 5
  23. Exercise 24, problem 6, p. 62

    $6a^{2} - 7a-3$ by $2a - 3$.

    Printed answer:
    • $3a + 1$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 3*a + 1
  24. Exercise 24, problem 7, p. 62

    $4a^{2} + 23a + 15$ by $4a + 3$.

    Printed answer:
    • $a + 5$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a + 5
  25. Exercise 24, problem 8, p. 62

    $3a^{2} - 4a-4$ by $2 - a$.

    Printed answer:
    • $-3a - 2$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -3*a - 2
  26. Exercise 24, problem 9, p. 62

    $x^{4} + x^{2} + 1$ by $x^{2} + x + 1$.

    Printed answer:
    • $x^{2} - x + 1$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x**2 - x + 1

Exercise 25

  1. Exercise 25, problem 1, p. 63

    Add $2a^{2} - 3ac - 3ab$; $2b^{2} + 3ac + a^{2}$; $-a^{2} - 2b^{2} + 3ab$.

    Printed answer:
    • $2a^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 2*a**2
  2. Exercise 25, problem 10, p. 63

    Add $-2a^{4} + 3a^{3}b - 4a^{2}b^{2}$; $2a^{3}b - 3a^{2}b^{2}$; $7a^{2}b^{2} + 2a^{4} - b^{4}$.

    Printed answer:
    • $5a^{3}b - b^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 5*a**3*b - b**4
  3. Exercise 25, problem 11, p. 63

    From $3x^{3} + 5x - 1$ take the sum of $x - 5 + 5x^{2}$ and $3 + 4x -3x^{2}$.

    Printed answer:
    • $3x^{3} - 2x^{2} + 1$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 3*x**3 - 2*x**2 + 1
  4. Exercise 25, problem 12, p. 63

    The minuend is $9c^{2} + 11c - 5$, and the remainder is $6c^{2} - 13c + 7$. What is the subtrahend?

    Printed answer:
    • $3c^{2} + 24c - 12$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 3*c**2 + 24*c - 12
  5. Exercise 25, problem 13, p. 63

    Find the remainder when $a^{4} + 6b^{4}$ is divided by $a^{2} + 2ab + 2b^{2}$.

    Printed answer:
    • $2b^{4}$.

    unverified: no computed check settled this one (yet)

    How it was checked
    • other: not a kind the checker handles 2*b**4
  6. Exercise 25, problem 14, p. 63

    Multiply $2 - 5x^{2} - 4x$ by $5 + 2x - 3x^{2}$.

    Printed answer:
    • $10 - 16x - 39x^{2} + 2x^{3} + 15x^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 10 - 16*x - 39*x**2 + 2*x**3 + 15*x**4
  7. Exercise 25, problem 15, p. 63

    Divide $a^{6} + a^{5}x + a^{4}x^{2} - a^{3}x^{3} + x^{6}$ by $a^{2} + ax + x^{2}$.

    Printed answer:
    • $a^{4} - ax^{3} + x^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**4 - a*x**3 + x**4
  8. Exercise 25, problem 16, p. 63

    $ax^{3} - cx + bx^{2} - bx^{3} + cx^{2} - x$.

    Printed answer:
    • $(a - b)x^{3} + (b + c)x^{2} - (c + 1)x$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes (a - b)*x**3 + (b + c)*x**2 - (c + 1)*x
  9. Exercise 25, problem 17, p. 63

    $ax^{4} - 2x + bx^{4} - cx - ax^{3} + bx^{3}$.

    Printed answer:
    • $(a + b)x^{4} - (a - b)x^{3} - (c + 2)x$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes (a + b)*x**4 - (a - b)*x**3 - (c + 2)*x
  10. Exercise 25, problem 18, p. 63

    $x^{3} - bx^{2} - cx + bx - cx^{2} + ax^{3}$.

    Printed answer:
    • $(a + 1)x^{3} - (b + c)x^{2} + (b - c)x$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes (a + 1)*x**3 - (b + c)*x**2 + (b - c)*x
  11. Exercise 25, problem 2, p. 63

    Subtract $3a^{4} - 2 a^{3}b + 4 a^{2}b^{2}$ from $4b^{4} - 2 ab^{3} + 4 a^{2}b^{2}$.

    Printed answer:
    • $-3a^{4} + 2a^{3}b - 2ab^{3} + 4b^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes -3*a**4 + 2*a**3*b - 2*a*b**3 + 4*b**4
  12. Exercise 25, problem 3, p. 63

    Simplify $x - y - \{z - x - (y - x + z)\}$.

    Printed answer:
    • $x$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes x
  13. Exercise 25, problem 4, p. 63

    Multiply $a^{2} + b^{2} + c^{2} - d^{2}$ by $a^{2} + b^{2} - c^{2} + d^{2}$.

    Printed answer:
    • $a^{4} + 2a^{2}b^{2} + b^{4} - c^{4} + 2c^{2}d^{2} - d^{4}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**4 + 2*a**2*b**2 + b**4 - c**4 + 2*c**2*d**2 - d**4
  14. Exercise 25, problem 5, p. 63

    Divide $10y^{6} + 2 - 12y^{5}$ by $1 + y^{2} - 2y$.

    Printed answer:
    • $10y^{4} + 8y^{3} + 6y^{2} + 4y + 2$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 10*y**4 + 8*y**3 + 6*y**2 + 4*y + 2
  15. Exercise 25, problem 6, p. 63

    If $a = 1$, $b = 2$, and $c = -3$, find the value of $a^{2} + b^{2} + c^{2} + 2ab + 2ac + 2bc$.

    Printed answer:
    • $0$.

    verified: the printed answer passed a computed check

    How it was checked
    • evaluate: passes 0
  16. Exercise 25, problem 7, p. 63

    Simplify $x - (y - z) - \bigl\{4y + [2y - (z - x)]\bigr\}$.

    Printed answer:
    • $2z - 7y$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 2*z - 7*y
  17. Exercise 25, problem 8, p. 63

    Multiply $a^{2} + b^{2} + c^{2} - ab - ac - bc$ by $a + b + c$.

    Printed answer:
    • $a^{3} - 3abc + b^{3} + c^{3}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes a**3 - 3*a*b*c + b**3 + c**3
  18. Exercise 25, problem 9, p. 63

    Divide $16y^{4} - 21x^{2}y^{2} + 21x^{3}y - 10x^{4}$ by $4y^{2} - 5x^{2} + 3xy$.

    Printed answer:
    • $4y^{2} - 3xy + 2x^{2}$.

    verified: the printed answer passed a computed check

    How it was checked
    • identity: passes 4*y**2 - 3*x*y + 2*x**2