Gas mileage depends in part on the speed of the car. The gas mileage of a luxury car is given by L(x) = -0.015x² +1.44x-21, where 25 ≤ x ≤ 70 represents the speed in miles per hour and L(x) is given in miles per gallon. At what speed will the car get the maximum gas mileage? What is the maximum gas mileage, in miles per gallon, for this car?
