<em>Question:</em>
<em>Sal is trying to determine which cell phone and service plan to buy for his mother. The first phone costs $100 and $55 per month for unlimited usage. The second phone costs $150 and $51 per month for unlimited usage. </em>
<em>The inequality that will determine the number of months, x, that are required for the second phone to be less expensive is . </em>
<em>The solution to the inequality is . </em>
<em>Sal’s mother would have to keep the second cell phone plan for at least months in order for it to be less expensive.</em>
Answer:
a.
b.
c. At least 13 months
Step-by-step explanation:
Given
First Phone;
<em>(monthly)</em>
Second Phone;
<em /><em> (monthly)</em>
<em></em>
Solving (a): The inequality
<em></em>
Represent the number of months with x
The first phone is expressed as:
The second phone is expressed as:
For the second to be less expensive that the first, the inequality is:
Solving (b): Inequality Solution
Collect Like Terms
Solve for x
Solving (c): Interpret the solution in (b)
implies 13, 14, 15....
Hence, She'll keep the second phone for a period of at least 13 months