"BUSINESS: Saini Sprinkler Company installs irrigation systems. To track monthly costs C and revenues R, they use the following functions, where x is the number of systems they install:

R(x) = 8x2 + 12x + 4

C(x) = 7x2 + 20x - 12

The monthly profit can be found by subtracting cost from revenue:

P(x) = R(x) - C(x)