What is the coefficient in the following expression?
5a to the 2 power subtracted by 7
a)7
d)2
c)5
b)a

One cell phone plan charges $20 per month plus $0.15 per minute used. a second cell phone plan charges $35 per month plus $0.10 per minute used. write and solve an equation to find the number of minutes you must talk to have the same cost for both calling plans.