Worked-out Problems

Chapter 3 continued
28. h 19 ≤ 15
h 19 19 ≤ 15 19
h ≤ 4
6 5 4 3 2 1
29. 18.1 ≤ p 7
18.1 7 ≤ p 7 7
25.1 ≤ p, orp ≥ 25.1
0
37. q 4 16 ≥ 30
q 20 ≥ 30
q 20 20 ≥ 30 20
q ≥ 10
5
0 5 10 15 20 25
38. Let x the temperature in F at which the bacteria
can survive.
x ≥ 280
25 25.2 25.4 25.6 25.8 26
30. t 7 < 3.4
t 7 7 < 3.4 7
t < 10.4
10 10.2 10.4 10.6 10.8 11
31. b 2.5 ≤ 2.5
b 2.5 2.5 ≤ 2.5 2.5
b ≤ 0
3 2 1 0 1 2 3
32. a 10.2 > 5.3
a 10.2 10.2 > 5.3 10.2
a > 15.5
15 15.2 15.4 15.6 15.8 16
33. Let x the temperature in F at which neon is a gas.
x ≥ 411
413 411 409 407
34. 5 m 8 ≥ 14
m 13 ≥ 14
m 13 13 ≥ 14 13
m ≥ 1
300
280
39. No. Sample answer: It is not possible to check all the
numbers that are solutions of an inequality because a
solution consists of an infinite amount of numbers.
No. Sample answer: Checking one number does not
guarantee that a solution is correct.
40. a. Let w the weight in pounds you can add to the
first bag.
Weight you
can add
≤
w 14 ≤ 50
w 14 14 ≤ 50 14
w ≤ 36
You can add at most 36 pounds of personal belongings
to the first bag.
b. Let w the weight in pounds you can add to the
second bag.
Weight you
can add
260
Weight
of bag
Weight
of bag
240
≤
Weight
limit
Weight
limit
w 21 ≤ 50
w 21 21 ≤ 50 21
w ≤ 29
You can add at most 29 pounds of personal belongings
to the second bag.
41. x ≥ 1 and x ≤ 4
3
2
1
0 1 2 3
1
0 1 2 3 4 5
35. 13 n 26 < 38
n 13 < 38
n 13 13 < 38 13
n < 51
47
48
49
50 51 52 53
36. 2.35 p 14.9 > 49.25
p 17.25 > 49.25
p 17.25 17.25 > 49.25 17.25
p > 32
42. x < 3 and x ≥ 0
1
43. Let x the temperature of ski wax in C.
x ≥ 6
x ≤ 15
x ≥ 6 and x ≤ 15
6
10 5
0 1 2 3 4 5
0 5 10 15 20
0
8
16
24 32 40 48
92 Pre-Algebra
Chapter 3 Worked-Out Solution Key
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