A rental car agency charges $26.00 per day and 25 cents per mile.
(a) Calculate the rental charge if you rent a car for 4 days and drive 300 miles. (Round your answer to the nearest cent.) $
(b) Use a formula to express the cost of renting a car as a function of the number of days you keep it and the number of miles you drive. (Let d be the number of days you rent the car, m the number of miles you drive the car, and C the cost in dollars of renting the car.) C(d, m) =