Cumulative Review Chapters R–5, p. 574
1. 3.
✓
5. ; ; Since they are inverse
functions. 7. a.
b. , triple births increase by 455 each year
c. sets of triplets, sets of triplets
9.
11. 13.
15. a. b. c.
17. is an extraneous root 19. a. about 88 hp for sport
wagon, about 81 hp for minivan b. rpm c. minivan, 208 hp
at 5800 rpm 21. 23. ,
25.
CHAPTER 6
Exercises 6.1, pp. 586–591
1. inconsistent 3. consistent, independent 5. Multiply the first
equation by 6 and the second equation by 10. 7.
9. 11.
13.
15. yes
17. yes
19.
10 10
10
10
Y
1
12 3X
2
, Y
2
X 9
x
y
108642
10
8
6
4
2
2
4
6
8
10
4
6
8
10
2
(6, 3)
x 3y 3y x 2,
x 3y 3y x 2y
4
3
x 5
y
7
4
x 6,
x ⬇ 2.013, x ⬇ 3.608
x ⬇ 4.967x ⬇ 0.649x ⬇ 5.064
⬇3294
x 5, x 6
f
1
1
f 1x22 x
x
y
108642
10
8
6
4
2
2
4
6
8
10
4
6
8
10
2
f
1
1x2
5x 3
2
2
2V
a
bx 3, x 2 1multiplicity 22; x 4
h1x2c: x 僆 12, 02 ´ 13, q2 h1x2T: x 僆 10, 32
D: x 僆 310, q2, R: y 僆 39, q2
x
y
108642
10
8
6
4
2
2
4
6
8
10
4
6
8
10
2
T1172 10,380T162 5375
¢T
¢t
455
1
T1t2 455t 2645 11991 S year 12
1f ⴰ g21x2 1g ⴰ f 21x2,g1f 1x22 xf 1g1x22 x
0 09 40i 32 40i 41 0
14 5i2
2
814 5i2 41 0
x 2 7i
21.
23. 25. 27. second equation, y,
29. second equation, x, 31. second equation, x,
33. 35. 37. 39. 41.
43. 45. 47. 49. (2, 8); consistent/
independent 51. ; inconsistent 53. consistent/
dependent 55. (4, 1); consistent/independent 57.
consistent/independent 59. consistent/independent 61. 1 mph,
4 mph 63. 2318 adult tickets; 1482 child tickets 65. premium: $3.97,
regular: $3.87 67. nursing student $6500; science major $3500
69. 150 quarters, 75 dimes 71. a. 3 mph b. 5 mph 73. a. 3.6 ft/sec
b. 4.4 ft/sec 75. a. 100 lawns/mo b. $11,500/mo 77. a. 1.6 billion
bu, 3 billion bu, yes b. 2.7 billion bu, 2.25 billion bu, yes c. $6.65,
2.43 billion bu 79. about 227 boards at $410 a piece
81. about 90,000,000 gal at $3.04 gal 83. 1776; 1865 85. Tahiti:
402 mi
2
, Tonga: 290 mi
2
87. 89. $50,000
91.
93.
Exercises 6.2, pp. 599–602
1. triple 3. equivalent, systems 5. 7. Answers will vary.
9. Answers will vary. 11. yes, no; R2, R3 13. (5, 7, 4) 15. (2, 4, 3)
17. (4, 0, 3) 19. (5, 12, 13) 21. no solution, inconsistent
23. ,
other solutions possible
25. ; ,
other solutions possible
27. 29.
31. 33.
35. 37. (12, 6, 4) 39.
41. 43. 45. (5 cm, 3 cm, 4 cm)
47. $80,000 at 4%; $90,000 at 5%; $110,000 at 7% 49. World War II,
1945; Korean, 1953; Vietnam, 1973 51. Declaration of Independence,
1776; 13th Amendment, 1865; Civil Rights Act, 1964 53. 1 L 20%
solution; 3 L 30% solution; 6 L 45% solution 55. saturated: 1.2 g,
monounsaturated: 1.0 g, polyunsaturated: 0.6 g 57. h(t) 5t
2
30t 1;
a. 46 ft b. 17.2 ft 59. 2 61. 63.
Mid-Chapter Check, p. 603
1. (1, 1) consistent 2. (5, 3) consistent 3. 20 oz 4. No; R2, R3
5. 6. (1, 2, 3) 7. (1, 2, 3) 8.
9. Morphy: 13, Mozart: 8, Pascal: 16 10. prelude: 2.75 min, storm:
2.5 min, sunrise: 2.5 min, finale: 3.25 min
1p, p 5, p 422R1 R2
x 131,
3
2
4
a
1
5
,
1
2
, 2b11, 2, 32
11, 5, 621p 17, p 4, p2
a1,
3
2
, 2be1x, y, z2`x
1
2
y 2z 6f
1p 9, p 4, p21p, 2p, p 12
a
5
3
p
2
3
, p 2, pbe1x, y, z2
|
x
5
3
z
2
3
, y z 2, z 僆 ⺢ f
1p, 2 p, 2 p251x, y, z2
|
x 僆 ⺢, y 2 x, z 2 x6;
z 5
x
y
108642
10
8
6
4
2
5
10
15
20
25
10
15
20
25
5
x 僆 32, 84
1x 521x 221x 1213x 12
y 2x 3
1
1
2
,
4
3
2;
13, 42;
51x, y2
|
6x y 226;
16, 12213, 4212, 32
1
11
2
, 2212, 3213, 1212, 1212,
5
2
2
1
5
2
,
7
4
2110, 12
14, 3213, 5214, 12
10 10
10
10
Y
1
5 5X
2
, Y
2
16 X
3
x
y
108642
10
8
6
4
2
2
4
6
8
10
4
6
8
10
2
(1, 5)
Student Answer Appendix SA-33
cob19545_saa_018-038.qxd 11/29/10 2:01 PM Page SA-33