Answer:
See explanation
Explanation:
Let x be the number of minutes Charlene uses her phone per month and $y be the charge (in dollars) for x minutes of usage the phone.
A. Cell Plus gives unlimited minutes for $50/month. This paln doesn't depend on time, so

A1 Cell offers a $40 monthly fee, plus $0.05/min for any time over 300 min per month, then

B. Attached diagram shows the graphs of these two functions.
C. The point of intersection is (500,50) and it represents the number of minutes x=500 when to plans have the same charges.
D. 10 hours = 600 minutes.
Cell plus charge = $50
A1 Cell charge

Charlene has to choose Cell plus plan in this case.
6 hours = 360 minutes
Cell plus charge = $50
A1 Cell charge

Charlene has to choose A1 Cell plan in this case.