Alexandra wants to sign up for cell phone service she trying to decide which company she should choose. Telecorp has a flat rate of 7 cents per minute, America's charges 25cents per call and phone busters charges 35 cents per call and 2 cents per min

Step-by-step explanation:

Let us assume that she makes 10 minutes of call.

Telecorp has a flat rate of 7 cents per minute. If she uses this cell phone service, the amount that she would pay for 10 minutes of call is

0.07 * 10 = $0.7

America's charges 25cents per call. If she uses this cell phone service, the amount that she would pay for 10 minutes of call is $0.25

Phone busters charges 35 cents per call and 2 cents per min. If she uses this cell phone service, the amount that she would pay for 10 minutes of call is

0.35 + 10 * 0.02

= 0.35 + 0.2

= $0.55

The cheapest service is that of America's. Therefore, she should choose it.