Question

Explain how inequalities can be used to compare phone plans.

Short answer

The result is shown in the solved exampls.

Step-by-step solution

Step 1. Given information.

Kuni is trying to decide between two rate plans offered by a wireless phone company.

$\begin{array}{ccc}& \text{Plan\hspace{0.17em}1}& \text{Plan\hspace{0.17em}2}\\ \text{Monthly\hspace{0.17em}\hspace{0.17em}Access\hspace{0.17em}\hspace{0.17em}Fee}& \$35.00& \$55.00\\ \text{Minutes\hspace{0.17em}\hspace{0.17em}Included}& 150& 400\\ \text{Additional\hspace{0.17em}\hspace{0.17em}Minutes}& 40& 35\end{array}$

Step 2. Write the inequalities.

To compare these two rate plans, use inequalities.

The minutes included for plan 1 is less than plan 2. That is,

$150>400$

The additional minutes fee for plan 1 is greater than that of plan 2. That is,

$40>35$

Step 3. Explain why plan 1 cheaper than plan 2.

The monthly access fee for plan 1 is less than the fee for plan 2. That is,

$\$35<\$55$

This shows that plan might be cheaper than plan 2 if Kuni uses more than 150 minutes less than 400 minutes.