Question 432643: A grandmother agrees to purchase a cell phone for emergency use only. AT&T now offers such a plan for $9.99 per month and $0.07 for each minute, t, the phone is in use.
A) write a linear function that describes the monthly cost C in terms of the time in minutes the phone is used.
B)If the grandmother used her phone for 20 minutes during the first month, what was her bill? Answer by jorel1380(2518) (Show Source):