College Algebra 9th txtbk

SA-26
Student Answer Appendix
43. c 5 2
0 1 1
19 9 7
1 0 1
9 15 10
2
1 1
45. c 3 7 51. £ 1 1 1 § 53. £ 15 7 6§
55. £ 2 2 1 § 59. £ 4 5 4 §
1 d 2 5 d
1 1 0
2 1 1
2 1 4
1 1 1
81. (A) (AB) 1 29 41
c
12 17 d , A1 B 1 23 33
c
16 23 d ,
B 1 A 1 29 41
c
12 17 d
83. 61 22 96 38 115 43 131 47 68 27 110 43 85. BEYONCE KNOWLES
87. 42 43 88 33 101 40 61 62 40 49 40 103 72 56 69 52 81 99 53 101
89. RAIDERS OF THE LOST ARK
91. Concert 1: 6,000 $20 tickets, 4,000 $30 tickets
Concert 2: 5,000 $20 tickets, 5,000 $30 tickets
Concert 3: 3,000 $20 tickets, 7,000 $30 tickets
` ` `
` Exercises 7-5
19. x 6 5, y 3 5 21. x 4 6 5 1
4 6
23. 25. 27. 29. (1) 23 5 1
17, 2 y 20
17
2 8`
0 2 (1)11 2 8` 44
0 2 10
47. x 4 3, y 1 3, z 2 3 49. x 9, y 7 3, z 6 51. x 3 2, y 7 6, z 2 3
53. If a 3 and b 15 there are an infinite number of solutions. If a 3 and b 15 there are no solutions. If a 8 2
4 ,
2
4 ,
3, there is one solution.
71. (A) Since D 0, the system either has no solution or infinitely many. Since x 0, y 0, z 0 is a solution, the second case must hold.
(B) Since D 0, by Cramer’s rule, x 0, y 0, z 0 is the only solution.
73. (A)
(B)
R 200p 300q 6p 2 6pq 3q 2
p 0.3x 0.4y 180, q 0.2x 0.6y 220,
Chapter 7 Review Exercises
3. Infinitely many solutions [t, (4t 8)3], for any real number t (7-1)
7. c 3 6 (7-2) 13. c 4 8
3 3
(7-3) 17. c (7-3)
1 4 ` 12
12 18 d
4 9 d
23. (A) x 1 1, x 2 3 (B) x 1 1, x 2 2 (C) x 1 8, x 2 10 (7-4)
27. x 1 2, x 2 2; each pair of lines has the same intersection point. (7-1, 7-2)
5 d R 180x 220y 0.3x 2 0.6xy 0.6y 2
5
5
5
5
x 2
(2, 2)
5 5
x 1
x 2
(2, 2)
5 5
x 1
x 2
(2, 2)
5 5
x 1
x 2
(2, 2)
5 5
x 1
5
x 1 x 2 4
2x 1 x 2 2
x 1 x 2 4
3x 2 6
x 1 x 2 4
x 2 2
7 16 9
12 24 6
35. £ 28 40 30 § (7-3) 37. 0 0 0§
(7-3)
$46.35 $41.00 Desks
LH c
$30.45 $27.00 d Stands
(7-3)
21 8 17
8 16 4
57. (A) $27 (B) Elements in LH give the total cost of manufacturing each product at each plant.
(C) North South
Carolina Carolina
x 1 2
x 2 2
CHAPTER 8 Exercises 8-1
99
101
1
10 1
100 1
1,000
15. 19. 25. 0.3, 0.33, 0.333, 0.3333, 0.33333 55. 1
57.
1.5
0
20
0
20
4
0.3
1.5
59. 1 8 2 16 3 32 4 73. (A) 3, 1.83, 1.46, 1.415 (B) Calculator 12 1.4142135. . . (C) a 1 1; 1, 1.5, 1.417, 1.414