Answer:
In this item, it is assumed that we are to determine the speed at which the car will have the best gas mileage. This can be done by deriving the equation and equating it to zero. M(s) = -1/28s² + 3s - 31Deriving, dM(s) = (-1/28)(2s) + 3 = 0 s = 42Hence, the speed at which the best mileage is achieved is mi/h.
Step-by-step explanation: