4.2 book answers

Copyright © by McDougal Littell, a division of Houghton Mifflin Company.
Answers for 4.2
For use with pages 182–184
4.2 Guided Practice
1. False; for any point on the line,
x 1 y is equal to 4, not greater
than 4.
2. True. Sample answer: (0, 0) is
a solution of the inequality and
since (0, 0) lies below the line
y 5 3x 1 5, the half-plane that
contains (0, 0), the half-plane
below the line, is the graph of
y < 3x 1 5.
3. True; the symbol ≥ means that
points on the boundary line are
solutions of the inequality.
4. not a solution 5. solution
6. solution 7. solution
8. solution 9. solution
10. dashed line 11. solid line
12. dashed line 13. B
14. C 15. A
4.2 Practice and Applications
16. not a solution; not a solution
17. solution; solution
18. not a solution; solution
19. not a solution; solution
20. solution; not a solution
21. solution; solution
22. solution; not a solution
23. solution; solution
24.
25.
26.
y
1
2
5
y
y
5
1 x
2 x
Algebra 2 Concepts and Skills
Answer Transparencies for Checking Homework A
x

Copyright © by McDougal Littell, a division of Houghton Mifflin Company.
Answers for 4.2 continued
For use with pages 182–184
27.
28.
29.
y
1
y
1
y
4
1
1 x
30. The graph consists of the solid
vertical line x 5 c and all the
points to the right of the line.
31. The graph consists of all
the points below the dashed
horizontal line y 5 c.
4
x
x
32. B 33. A
34. C
35.
36.
37.
1
y
2
y
1
y
2
2 x
2
Algebra 2 Concepts and Skills
Answer Transparencies for Checking Homework A
x
x

Copyright © by McDougal Littell, a division of Houghton Mifflin Company.
Answers for 4.2 continued
For use with pages 182–184
38.
39.
40.
y
2
y
1
y
2
2
1
2
x
x
x
41.
42.
43.
y
2
2
y
2
44. 4x 1 30y ≤ 600
y
2 x
2
2
Algebra 2 Concepts and Skills
Answer Transparencies for Checking Homework A
x
x

Copyright © by McDougal Littell, a division of Houghton Mifflin Company.
Answers for 4.2 continued
For use with pages 182–184
45.
Helmets
y
90
80
70
60
50
40
30
20
10
25 100 150 200
Baseballs
46. Sample answer: 20 baseballs
and 15 helmets, 30 baseballs and
16 helmets, 40 baseballs and
14 helmets
47. 300m 1 275y ≥ 1300
48.
Yogurt (c)
y
1
1
Skim milk (c)
49. Sample answer: 4 cups of skim
milk and 1 cup of yogurt,
2.5 cups of milk and 2 cups of
yogurt, 3 cups of milk and
1.5 cups of yogurt
50. 10r 1 0.6t > 58
x
m
51.
Temperature (F)
t
100
90
80
70
60
50
40
30
20
10
0.2 0.6 1 1.4 1.8 r
Relative humidity
52. Sample answer: 0.5 and 908F,
0.6 and 888F, 0.8 and 868F
53. 1.4x 1 6.2y ≤ 100
54.
Movie Clips
y
45
40
35
30
25
20
15
10
5
10 20 30 40 50 60 70 80 90
Photographs
55. Sample answer: 50 photographs
and 3 video clips, 40 photographs
and 7 video clips, 25 photographs
and 10 video clips
Algebra 2 Concepts and Skills
Answer Transparencies for Checking Homework A
x

Copyright © by McDougal Littell, a division of Houghton Mifflin Company.
Answers for 4.2 continued
For use with pages 182–184
56. Sample answer: y ≤ 2 3
}
5 x 1 3.
Sample answer: From the graph,
the y-intercept is 3 and the slope
is 2 3
}
5 , so the boundary line has
equation y 5 2 3
} x 1 3. The
5
boundary line is solid, so the
solution includes points on the
boundary line. (0, 0) is a solution,
so the inequality is y ≤ 2 3
} x 1 3.
5
4.2 Standardized Test Practice
57. a, b. y 5 0.99x 1 30;
Cost (dollars)
y
180
160
140
120
100
80
60
40
20
20 60 100 140 180
Miles
c. Sample answer:
y 5 0.99x 1 25; see graph
above.
x
4.2 Mixed Review
58.
59.
60.
y
1
1
y
2
y
1
2
1
y 8
x 5
2
Algebra 2 Concepts and Skills
Answer Transparencies for Checking Homework A
x
x
4
y x 1
3
x

Copyright © by McDougal Littell, a division of Houghton Mifflin Company.
Answers for 4.2 continued
For use with pages 182–184
61.
62.
63.
64. (1, 1)
65. (2, 24)
66. (21, 5)
y
1
y
4
2
1
x
1
y x 3 2
2
x 4y 8
2
x
y
5x 2y 12
x
4.2 Geometry Skills
67.
68.
A
B
A
1
C
y A
y
B
B
A B
D C
1
C
2
D C
Algebra 2 Concepts and Skills
Answer Transparencies for Checking Homework A10
x
x