A car rental company charges an initial fee plus an additional fee for each mile driven. the charge depends on the type of car: economy or luxury. the charge e (in dollars) to rent an economy car is given by the function e=0.80m+15.95, where m is the number of miles driven. the charge l (in dollars) to rent a luxury car is given by the function l=1.15m+21.40. let c be how much more it costs to rent a luxury car than an economy car (in dollars). write an equation relating c to m. simplify your answer as much as possible.
