home work question section 4.6 calculus

Question

A store rents movies. If the rental fee is

​$2

​each, the store knows they can rent

90

movies per week. For each additional​ $1 increase in the rental​ fee, the store loses

9

rentals per week. What rental fee should the store charge for a movie to maximize their​ revenue?

Answer 1

x represents the number of $1 increases

f(x) = (90 - 9x)(2 + 1x)

Can you convert to standard form and answer?