Please show the work

The Appalachian Coal Mining believes that it can increase labor productivity and therefore, net revenue by reducing air pollution in its mines. It estimates that the marginal cost function for reducing pollution by installing additional capital equipment is: MC = 40P

Where P represents a reduction of one unit of pollution in the mines. It also estimates that for every unit of pollution reduction the marginal increase in revenue (MR) is: MR = 1,000 10P

How much pollution reduction should Appalachian Coal Mining undertake?