1. Systems of Linear Inequalities
ALGEBRA 1 LESSON 7-6
pages 380–384  Exercises
1. no
2. yes
3. no 4. 5. 9.
10.
11. 6. 7. 8.
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2. Systems of Linear Inequalities
ALGEBRA 1 LESSON 7-6
16. x > 5 and y –x + 3
17. y – x – 2 and y x + 2
18. y – x + 1 and y – x + 3
19. y – x – 4 and y x – 3
20. a. 1.5f + 2.5c < 9.50, f + c > 4 b.
21.
12.
13.
14.
15.
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22. a. 5.99x y 50,
x 0, y 1 b.
c. 2 books and 6 CDs;
no, (2, 6) is not in the
shaded region.
d. Answers may vary.
Sample: 3 books and
3 CDs for $47.94
< – 1 2 1 2
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< – 1 5 3 4
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> – 2 3 1 5
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3. Systems of Linear Inequalities
ALGEBRA 1 LESSON 7-6
25. x 3, x –3, y 3, y –3
26. y 2, x < 5, y x
27. y x – 2, y < x + 2
28. y –x – 3, y –x + 3, y x + 3, y x – 3
29. Answers may vary.
Sample: x –2, x 4, y 1, y –2
30. a. –1     
b. 8
31. a. triangle     
b. (2, 2), (–4, –1), (–4, 2)     
c. 9 units2
23. x + y 30, 1.25x + 3y 60
24. a. x + y 12, 6x + 4y 60
b. Answers may vary. Sample:
(8, 3), (9, 1), (10, 0)
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< – 2 3 2 3
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4. Systems of Linear Inequalities
ALGEBRA 1 LESSON 7-6
32. a. square
b. (1, –1), (5, –1), (1, 3), (5, 3)
c. 16 units2
33. a. trapezoid
b. (0, –4), (0, 2), (2, –4), (2, 0)
c. 10 units2
34. a. triangle
b. (2, –3), (2, 2), (7, –3)
c units2
35. a. x 1, 10.99x y 45
b. (3, 0), (3, 1), (3, 2), (4, 0)
36. a.
b. No; they are parallel.
c. no
d. no
37. a.
c. It is a strip between the lines.
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5. Systems of Linear Inequalities
ALGEBRA 1 LESSON 7-6
38–42. Answers may vary. Samples are given.
38. x 1 and y 2
39. x < 0 and y > 0
40. y > 5 and y < 3
41. x < 2 and y < 5
42. x > 0 and y < 0
43. a. s + d > 10, s + d < 20,
d 3, 10d s < 60
b. Answers may vary. Sample:
(8, 4.5); 12.5g; gold: $45.00, silver: $1.20
44.
45. Answers may vary.
y > x, y < 2x
46. Answers may vary.
y > x + 1, y > –x + 1
47. a. h a b.
c. Answers may vary.
Sample: 5 hits, 6 at-bats
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6. Systems of Linear Inequalities
ALGEBRA 1 LESSON 7-6
48. a. 180x + 240y
x + y 17
x > y
y 4
b. Answers may vary. Sample:
ten 14-in. drums and
six 18-in. drums
49. D
50. G
51. [2] all points on the line 3x + 4y = 12
[1] incorrect description given
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52. [4] a. Let x = number of toppings,
and y = cost of pizza.
Maria’s: y = 0.50x + 8
Tony’s: y = 0.75x + 7
b. (4, 10)  With 4 toppings, the cost is
$10 at either Tony’s or Maria’s.
c. Answers may vary. Sample: Since
I prefer more than 4 toppings, I will
go to Maria’s, because the pizza will
be less expensive.
[3] (a) and (b) only done correctly
[2] (a) done correctly, but student makes a computational error in (b)
[1] error in (a), but system solved correctly
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7. Systems of Linear Inequalities
ALGEBRA 1 LESSON 7-6
59.
60. –3
61. –8
62. –
63. –
64. –
65.
66.
67.
68. ƒ(x) = 7x
69. ƒ(x) = x + 6
70. ƒ(x) = x 2 5 2
53.
54.
55.
56.
57.
58. 1 4 1 5 8 3 10 9 6 13 15 4
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