5-2 Solving Inequalities by Multiplication and Division
Define a variable, write an inequality, and solve each problem. Then interpret your solution.
10. CELL PHONE PLAN Mario purchases a prepaid phone plan for $50 at $0.13 per minute. How many minutes can
Mario talk on this plan?
ANSWER: Let m = the number of minutes that Mario can talk; 0.13m ≤ 50; m ≤ 384.6; Mario can talk up to 384 minutes.
Solve each inequality. Graph the solution on a number line.
12. ANSWER: {m | m ≤ –68}
14. ANSWER: {c | c > 121}
16. ANSWER: {x | x ≤ 20}
18. ANSWER: {h | h > 21}
20. ANSWER: {n | n ≥ 108}
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22. 4r < 64
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ANSWER: {h | h > 21}
5-2 Solving Inequalities by Multiplication and Division
20. ANSWER: {n | n ≥ 108}
22. 4r < 64
ANSWER: {r | r < 16}
24. −26 < 26t
ANSWER: {t | t > –1}
26. −33 ≥ −3z
ANSWER: {z | z ≥ 11}
28. −2d < 5
ANSWER: 30. CHEERLEADING To remain on the cheerleading squad, Lakita must attend at least
of the study table sessions
offered. She attends 15 sessions. If Lakita met the requirements, what is the maximum number of study table
sessions?
ANSWER: 25
32. CHARITY The National Honor Society at Pleasantville High School wants to raise at least $500 for a local charity.
Each student earns $0.50 for every quarter of a mile walked in a walk-a-thon. How many miles will the students
need to walk?
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ANSWER: at least 250 mi
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offered. She attends 15 sessions. If Lakita met the requirements, what is the maximum number of study table
sessions?
ANSWER: 5-2 Solving
Inequalities by Multiplication and Division
25
32. CHARITY The National Honor Society at Pleasantville High School wants to raise at least $500 for a local charity.
Each student earns $0.50 for every quarter of a mile walked in a walk-a-thon. How many miles will the students
need to walk?
ANSWER: at least 250 mi
34. GASOLINE If gasoline costs $3.15 per gallon, how many gallons of gasoline, to the nearest tenth, can Jan buy for
$24?
ANSWER: no more than 7.6 gal
Match each inequality to the graph of its solution.
a.
b.
c.
d.
36. 25j ≥ 8
ANSWER: a
38. 2.3 < −5t
ANSWER: c
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