Question

Supernova,an analytics firm, has determined that the weekly demand for a certain brand of computer headphones depends on the price of the headphones and is given by the function x=N(p)=10000-400p (0<= p<=25),
The firm has also predicted the total cost (in dollars) of manufacturing x headphones per week. the cost is given by C(x)=12000+1.5x
the total weekly revenue (in dollars) from the sale of the headphones is given by this function R(x)=10x -0.0005x^2
given this scenario
What is the total cost of manufacturing C as a function of the price of the headphones p? Please help :)