10.1 Factoring Common Monomials
1. 15
2. 3
3. 8x
4. relatively prime
5. x2y2 6. 2ab
7. 3(x + y)
8. a(x + y)
9. 8(x – 4y)
10. 15(x + 2)
12. 10(–5x + 1)
13. prime
14. x(x – 3)
15. 7(x2 – 7xy + 4y2) 16. 3(7x3 – 2x2 – 1) 17. 6(a2 + 8a – 4) 18. prime
19. 3ab(2a + b)
Section 10.1 23. prime
24. 2π(–2r + x)
25. 4x(3x2 – 4y2)
26. 10x(2a3 + 5a + 1) 27. 14x(4x + 3y – 2)
28. prime
29. 7a(a4 – 12a2 + 3) 30. x(x4 + x2 – x + 1) 31. (x – 2)(x + 8)
32. (2y – 1)(4y – 3)
33. (b + c)(5 + a)
34. (y – z)(6x – 7)
35. 42 in.2 = 1 in. × 42 in. = 2 in. × 21 in. = 3 in. × 16 in. = 6 in. × 7 in.
36. 12 children; 9 rows
37. 13 cookies
38. 3x – 1
39. 2π(x + y); x + y
40. 3x2y4z3(2x2y – 9xy2z + 6z2) 41. 17a2b5(2a5b3c2 + 3ad4 –
y
(2, 4) (4, 2) (21, 3)
(23, 1)
44. 1 km
45a. 555.6 m
45b. 1822 ft
45c. 405.6 m; 1330 ft
46. D = {–3, –1, 2, 4}
47. R = {1, 2, 3, 4}
48. yes
49. {(–3, 1), (–1, 3), (2, 4), (4, 2)}
50.
51. x2 – 3x – 40 52. x2 – 13x + 40 53. x2 + 3x – 40 54. 3x2 + 15x – 42
10.2 Factoring Trinomials of the Form x2 + bx + c
1. (a + 3)(a + 5)
2. (x + 6)(x + 9)
3. (a – 3)(a – 1)
4. (x + 8)(x – 4)
5. (b + 5)(b – 4)
6. (x + 1)(x – 3)
7. (a + 4)(a – 2)
8. (a + 7)(a – 4)
9. prime
10. prime
11. (x – 5)(x – 4)
12. (x – 10)(x – 1)
13. (y + 5)(y + 2)
14. prime
15. prime
16. (a – 15)(a + 2)
17. (x + 10y)2 18. (x + 3y)2
19. (x – 2y)(x – 48y)
20. (x – 3y)(x – 15y)
21. (a – 18b)(a + 4b)
23. (x + 4)(x + 14)
24. (y – 2)(y – 24)
25. (x – 3)(x + 18)
26. 6(b – 4)(b – 3)
27. 3(x – 9)(x + 1)
28. a(x – 12)(x + 1)
29. 3(x + 6)(x + 2)
30. 4(x – 8)(x – 3)
31. x2(x + 8)(x – 2)
32. (x – 4)(x – 14); 10 units
33. x2 + 32x + 60; (x + 30)(x + 2)
34. –ax(x + 3)(x – 48)
35. 4a2b(a + 2b)(a – 5b) 36. b(x2 – 24)(x2 + 5) 37.
Section 10.2 38b.
39.
40. y ≈ –0.5x + 978.3
41. trinomial
42. 8
43. 6
44. 7
45. x2y3(6x – 27yz + 8) 46. 6x2 + 29x + 35
10.3 Factoring Trinomials of the Form ax2 + bx + c
1. (2x + 3)(x + 4)
2. (4x + 3)(x + 3)
3. (x – 4)(3x – 2)
4. (3x – 5)2
5. (3x – 7)(x + 4)
6. (x – 3)(2x + 7)
7. (3x + 4)(2x – 1)
8. (3b + 2)(2b – 5)
9. (3c + 2)(5c + 3)
10. (3x + 2)(4x + 3)
11. (2a + 1)(3a – 4)
12. (3x – 1)(3x + 2)
13. (5x + 1)(x – 3)
14. (2x – 1)(x + 7)
15. (x + 3y)(5x – 7y)
16. (6x + 5y)(x – 4y)
17. 3(x – 2)(2x + 5)
18. 10(3x + 5)(x – 5)
19. 8(2a – b)(a + 3b)
20. 4(x + y)(3x – 5y)
21. (m – 5n)(m + 4n)
2
2
2 2
3x
5x
23. (x – 2y)(x + 5y)
24. (x + 7y)(x – 14y)
25. 2(x – 8)(x + 4)
26. 8(a + 1)(a – 14)
27. 3ab(b – 1)(4b + 7)
28. 17xy(x + 1)(3x – 5)
29. 3(5x + 3)(3x – 2)
30. 2(7x + 4)(2x – 3)
31. 2(x + 4y)(x – 13y)
32. 3(x – 11y)(x + 14y)
33. 6(8x – 3)(3x – 1)
34. a2b(a + 2)(3a – 5)
35. (5x + 4)(3x + 4)
36.
37. 5 : 3
Section 10.3
y
x
39. using the polynomial: 4(5)2 + 104(5) + 651
= 100 + 520 + 651 = 1271
using the factored form: [2(5) + 21][2(5) + 31] = (10 + 21)(10 + 31) = 31(41) = 1271
40. 304 ft2 41. 25x2 – 9 42. x = 9
43. (6, 2)
44. 2x2 + 4x + 9 45. 3x – 4
46. 5x + 2
47. x < 5
48.
49. 20 hr
10.4 Special Patterns
1. +, – or –, +
2. +, – or –, +
3. 2, 2
4. 10, 10
5. 6a, 7
6. 7, 5x
7. yes; 3x doubled = 6x
8. yes; 7x doubled = 14x
9. no; x2y is not a perfect square
11. no; 2x(5) doubled = 20x
12. no; – 4b2 is not a perfect square
13. (a – 15b)(a + 15b)
14. (ax – y)(ax + y)
15. (x – 3)2 16. (4a + 1)2 17. (x – 8)2 18. (m + 12)2 19. (a – 5b)2
Section 10.4 21. 2(a – 11)(a + 11)
22. 3(x – 7)(x + 7)
23. (3x + 2)2 24. (6x + 1)2
25. x2(a – 4)(a + 4) 26. a2(a – b)(a + b) 27. (3x + 5z)2
28. prime
29. 4(2x – 1)(2x + 1)
30. x5(x – 1)(x + 1) 31. prime
32. (x + 0.3)2
33. 7(3x – 5)(3x + 5)
34. 3(7a – 13)(7a + 13)
35. 18b4c(3a – 1)(3a + 1) 36. x2(x2 + 1)(x + 1)(x – 1) 37. 3xy(3x2 – 4y)2
38. (3x + 8)2;
2
9 48 64
3 8
3 8
x x
x x
+ +
= + +
39. 17,952 days ≈ 49 yr
41a. y ≈ –3.66x2 + 30.86x + 196.34
41b.
42. Friction between the side walls of the valley and the edges of the glacier causes the edges to move slower. Thicker ice in the center of the glacier allows for a
faster flow at the top of the glacier. The Internet
keyword search glacial
processes will provide some interesting information and diagrams.
43. –15
44. –3x + 6
Section 10.4
y
x
46.
47. –2323
48. 73 × 101
49. 2323
23 −
= –101 or
2323 101 −
− = 23;
7373
73 = 101 or 7373
101 = 73
50. 2(x + 2);
(2x + 4) ÷ 2 = (x + 2) or (2x + 4) ÷ (x + 2) = 2
51. –5x(8y2 – y – 4);
2
40 5 20
5
xy xy x x
− + +
− =
8y2 – y – 4 or
2
2
40 5 20
8 4
xy xy x y y
− + +
− − = –5x
52. (x – 1)(x + 9);
2 8 9 9 x x x + −
+ = x – 1 or
2 8 9 1 x x x + −
10.5 Factoring Completely
1. 5(a + 1)2 2. x(x – 1)2
3. 2(10 – a)(10 + a)
4. 2a6(2a – 1)(2a + 1) 5. 3(x – 2)(x – 4)
6. a3(3a2 – 4) 7. 5(x – 7)2 8. (m5 + 1)2
9. (x + y)(2x – y)
10. (4 – m)(b + c)
12. (x + 2)(t – 3w)
13. (a + b – 2)(m + n)
14. (m + n)(2a + b)
15. 8(a – 3b2)2
16. 3x(x – 4)(x – 7)
17. (x2 + 4)(x – 2)(x + 2)
18. (a2x2 + 9)(ax + 3)(ax – 3) 19. 3(3x + 4)(2x – 3)
20. 5(3y + 4)(2y – 5)
Section 10.5 23. (w + x)(y + z)
24. (x + 3)(y + 5)
25. (x + 7)(y – 6)
26. (x – 3y)(x – 2)
27. (x + 4)(6x + y2)
28. (x – y)(x + y)(2a + b)
29. (y – 2)(y + 2)(y – 3)
30. (a – 3)(a + 3)(a + 2)
31. 5(y – 1)(y + 1)(y – 3)
32. 3(x – 4)(x + 4)(x – 2)
33. (x – 2)(x + 3)(x – 4)
34. (x + 2)2(x – 3)
35. (y + 1)(y – 3)(2y – 5)
36. (y + 4)(y + 2)(3x – 1)
37. (x + y – 3)(x + y + 3)
38. [(x + y) + 1]2 or (x + y + 1)2 39a. 10,496 ft
39b. ≈ 2.3 × 106 ft3
40a. ≈ 0.44 = 44% grade
40b. ≈ 0.20 = 20% grade
41a. 0.8 km/min
41b. 30 mi/hr
43. q 7n 5 A
+ =
44. 24
11
m q =
45. 7
5
q
x
= +
46. 11 quarters, 13 dimes, and 7 nickels
47. 21 quarters, 14 dimes, and 7 nickels
48. plane: 183 mi/hr; wind: 8 mi/hr
49. current: 0.5 mi/hr; boys: 4.5 mi/hr
50. 1.875 gal of the 40%
solution and 1.125 gal of water
Chapter 10 Review
1. r(3r + 5)
2. 2x(4xy3 + 3y2 – 1) 3. 4x2(x – 2)
4. x2(x2 + 3xy + 7) 5. (y – 7)(y – 8)
6. (x + 9)(x – 6)
7. (2d + 7)(d + 1)
8. (3t – 1)(3t + 8)
9. (x + 7)(x – 2)
10. (a + 7)(a – 12)
11. (5b + 3)(3b – 2)
12. (2y + 1)(y + 7)
13. (a – 3)(a + 3)
14. (5x – 12y)(5x + 12y)
15. (a + 7)2 16. (3x – 5)2
17. y(x + 8)(x – 7)
18. 7(y – 2)(y – 1)
19. 2(9x – 5)(x – 5)
20. 4(3x – 5)(x – 4)
21. 2(x – 9)(x – 6)
23. prime
24. x(9x – 25)
25. 2(3y – 5)(3y + 5)
26. prime
27. 24(x – 2y)(x + 2y)
28. 5(b – 5)2 29. (3b – 2c)2
30. (2a – 3)(a + 6)
31. (3x – y)(5x + 2y)
32. (3y + 5)(y + 4)
33. prime
34. 6(2x + 3y)(x + 5y)
35. 2(3a – 7)(a – 1)
36. prime
37. 2(3y – 5)(2y + 7)
38. (9r + 2s)(r + 1)
39. (2x2 – 3)(5x + 7) 40. (x2 + 3)2
41. (c2 + 2)(c2 + 1)
42. (x + y – 3)(x + y + 3)
Chapter 10 Review 46. S = πr(l + r)
47. x2 + xy + y2
48. (2w + 7)(2w + 5)
49. 35 in.2 50a. 99 in.2
Sequences—Factorial Sequences
1. 3 × 2 × 1 = 6
2. 6 × 5 × 4 × 3 × 2 × 1 = 720
3. 8!
4. 5!
5. 2.667, 2.708, 2.717
6. 2.71806, 2.71825, 2.71828
7. 2.7182815, 2.7182818, 2.7182818