The fixed weekly cost is $3000, and variable costs for each pet are $20.
P(x) = R(x) - C(x)

a. Let x represent the number of virtual pets made and sold each week. Write the weekly cost function, C, for virtual Fido.

b. The function R(x) = -x^2+1000x describes the money that Virtual Fido takes in each week from the sale of x virtual pets. Use this revenue function and the cost function from part (a) to write the weekly function, P.

c. Use the profit function to determine the number of virtual pets that should be made and sold each week to maximize profit. What is the maximum weekly profit?