At a certain farm there are currently `a` acres of land grow…

At a certain farm there are currently `a` acres of land growing crops, and this amount of land is decreasing by `aprime` acres per year. The crops this year will earn a profit of about `p` dollars per acre. The cost of food is rising and profits are increasing at a rate of `pprime` dollars per acre per year. At what rate is the total profit of the farm changing this year? Note: You are being asked to compute the rate of change of the total profit, the problem gives you information about the profit of just one acre of land.   Desmos (click to reveal)