Ok, I'm pretty lost on this one.
A farmer will produce a crop of soybeans between 0 and 250 tons. The price of P of a single ton of soybean is $500 minus twice the number of tons X that are produced, since the unit price lowers as the farmer produces more. In addition, in order to partially control prices, the government pays the farmer an extra $200 for each ton produced. Use calculus to find the number of tons X that the farmer should produce to maximize the revenue received (total dollars earned from both the gov. and from selling X tons at price P).