Worked-out Problems

Chapter 3 continued
9. ––CONTINUED––
(3) 120 8v 8v < 33v 8v
120 < 25v
1 20
< 2 5v
25
25
4.8 < x, orx > 4.8
Sample answer: After 5 visits to the park, the cost of
the season pass will be less than the cost of visiting
without the season pass.
3.6 Practice and Problem Solving (pp. 151–153)
10. 5x 10 > 2x 4
5(8) 10 ? > 2(8) 4
30 > 20
30 > 20, so 8 is a solution.
11. 5x 10 > 2x 4
5(5) 10 ? > 2(5) 4
15 > 14
15 > 14, so 5 is a solution.
12. 5x 10 > 2x 4
5(4) 10 ? > 2(4) 4
10 < 12
10 < 12, so 4 is not a solution.
13. 5x 10 > 2x 4
5(2) 10 ? > 2(2) 4
20 < 0
20 < 0, so 2 is not a solution.
14. 2y 7 > 11
2y 7 7 > 11 7
2y > 4
2 y
> 4 2 2
y > 2
1
0 1 2
15. 6n 3 ≤ 9
6n 3 3 ≤ 9 3
6n ≤ 6
6 n
≤ 6
6 6
n ≤ 1
4 3 2 1
16. 11 4z < 1
11 4z 11 < 1 11
4z < 12
4
z
4
> 12
4
z > 3
3 4 5
0 1 2
0 1 2 3 4 5
100 Pre-Algebra
Chapter 3 Worked-Out Solution Key
6
17. 3m 8 > 30 5m
3m 8 5m > 30 5m 5m
2m 8 > 30
2m 8 8 > 30 8
2m > 22
2
m
2
< 22
2
m < 11
7 8 9 10
x
18. 19 ≥ 25 9 0
x
19 25 ≥ 25 25
9 0
x
44 ≥
9 0
x
90 p 44 ≥ 90 p
9 0
3960 ≥ x, orx ≤ 3960
3880 3920
19. 3 b 3 < 7
3 b 3 3 < 7 3
4
b 3 < 4
3 p b 3 < 3 p 4
b < 12
0 4 8
20. 14p 5 ≥ 3p 114
14p 5 3p ≥ 3p 114 3p
17p 5 ≥ 114
17p 5 5 ≥ 114 5
17p ≥ 119
1 7p
≥ 1 19
17
17
p ≥ 7
3 4 5 6 7 8 9
21. 3x 3 < 2x 83
3x 3 2x < 2x 83 2x
5x 3 < 83
5x 3 3 < 83 3
5x < 80
5
x
5
> 80
5
x > 16
11 12 13
3960 4000
12 16 20
0 4 8 12 16 20 24
Copyright © McDougal Littell/Houghton Mifflin Company
All rights reserved.