A car rental company charges $50 a day and 13 cents a mile for its cars.
(a) Write a formula for the dollar cost, C, of renting a car as a function of the number of days, d, and the number of miles driven, m.
(b) If C = f (d, m), find f (2, 120). Renting a car for 2 days and driving it 120 miles costs $ _____________.