a rental car company charges an upfront fee to rent a car, and then charges $0.40 per mile driven. it will cost you $60 to drive 50 miles. suppose you rent a car from this company. let n represent the varying number of miles that you drive in the car. let c represent the total cost (in dollars) you will have to pay for the rental car. how much is the upfront fee to rent the car? (that is, what is the total cost if you drive 0 miles?)