The polynomial function P(x) = 75x - 87,000 models the relationship between the number of computer

The polynomial function P(x) = 75x - 87,000 models the relationship between the number of computer briefcases x that a company sells and the profit the company makes, P(x). Find P (4000), the profit from selling 4000 computer briefcases.

Plug in 4,000 for x:
P(4000) = 75(4000) - 87,000
P(4000) = 300,000- 87,000
P(4000) = 213,000