(34 points) URGENT !! A car rental company’s standard charge includes an initial fee plus an additional fee for each mile driven. The standard charge S (in dollars) is given by the function S=15.75 + 0.50M, where M is the number of miles driven. The company also offers an option to insure the car against damage. The insurance I (in dollars) is given by the function I= 4.90 + 0.15M. Let C be the total charge (in dollars) for a rental that includes insurance. write an equation relating C to M. Simplify your answer as much as possible.