If $w$ pounds per acre of nitrogen fertilizer are spread on a corn field, the yield is $230 - 4300 / (w + 22)$ bushels of corn per acre. Corn sells for $4.25 per bushel, and fertilizer costs $0.50 per pound. All other costs of growing and harvesting the corn total $600 per acre and do not depend on the amount of fertilizer used.
A) How much nitrogen fertilizer per acre should the farmer use to maximize his net dollar return per acre? lb/acre
B) If the farmer uses the optimum amount of fertilizer, what will be his net dollar return per acre? $ per acre.