A cell phone company offers 2 talk and text plans. The company charges a monthly service fee of $20 for either plan the customer chooses:
Customers that choose plan A are charged 5 cents a minute and $20 for texts in addition to the monthly service fee
Customers that choose text plan b are charged 10 cents a minute (first 100 minutes free) and $15 for 200 texts. the equation c = .10 (m – 100) + 15 + 20 can be used to represent how much a customer would spend monthly for the minutes used.