A company that sells umbrellas can sell 5000 of them per month at $40 each. the company's research indicates that sales will drop by 100 umbrellas for every $1 increase in price. (1) choose the equation that represents the revenue. (2) what is the maximum revenue?
a)
R=5000×P

b) (R=(5000−100P)×(40+P)

c)
R=5000×(40−P)

d)
R=(5000+100P)×(40−P)