A car rental agency charges $75 per day plus 70 cents per mile. a. Express the cost of renting a car from this agency for 1 day as a function of the number of miles driven, and draw the graph. b. How much does it cost to rent a car for a l-day trip of 50 miles? c. The agency also offers a rental for a flat fee of $125 per day. How many miles must you drive on a l-day trip for this to be the better deal?