Question

1. davina is comparing cell phone plans. the first plan has a flat fee of $10 per month plus $0.04 per text message. the second plan has a flat fee of $5 per month plus $0.12 per text message. what is the difference in dollars of the two plans for sending 15 text messages each month for six months? n mp

Explanation:

Step1: Calculate the cost of the first plan for one month

The cost formula for the first plan is \(C_1 = 10+0.04x\), where \(x = 15\) (number of texts).

$$C_{1 - month}=10 + 0.04\times15=10+0.6 = 10.6$$

Step2: Calculate the cost of the first plan for six months

Multiply the one - month cost by 6.

$$C_{1 - six - month}=10.6\times6=63.6$$

Step3: Calculate the cost of the second plan for one month

The cost formula for the second plan is \(C_2=5 + 0.12x\), where \(x = 15\) (number of texts).

$$C_{2 - month}=5+0.12\times15=5 + 1.8=6.8$$

Step4: Calculate the cost of the second plan for six months

Multiply the one - month cost by 6.

$$C_{2 - six - month}=6.8\times6 = 40.8$$

Step5: Calculate the difference between the two six - month costs

$$Difference=C_{1 - six - month}-C_{2 - six - month}$$

$$Difference=63.6-40.8 = 22.8$$

Answer:

\(22.8\)