Need help with this Question. I can't find it in my textbook or online examples in the section for this chapter.

This que Find the rate of change of total revenue, cost, and profit with respect to time. Assume that R(x) and C(x) are in dollars. R(x) =50x - 0.5x , C(x) =3x + 5, when x = 30 and dx / dt = 25 units per day The rate of change of total revenue is $ per day. The rate of change of total cost is $ per day. The rate of change of total profit is $ per day