Decide if the function is an exponential growth function or exponential decay function, and describe its end behavior using limits y=(1/6)^-x

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.