Annie needs to change the price of a pile of sweaters. She is told to apply a discount function on each price, d(p)=0.85p, AND THEN increase the resulting price: r(p)=p+10. What is the function that Annie can use to calculate both price changes? * Answer Choices:
A. r(d(p))=0.85p+10
B. f(p)=0.85p+(p+10)
C. d(r(p))=0.85p+8.50
D. f(p)=0.85p⋅(p+10)

the revenue of the fitness center, y, is the product of two factors: the number of members and the fee paid by each member. there are 320 members now, but number of members goes down by 10 for each $5 increase in fees, so if x is the number of $5 price increases then members is equal to (320 - 10x). since the fee is currently $45, and the fee increases by $5 for every price bump x, the fee is given by (45 + 5x). so, revenue y is given by y = (320 - 10x)(45 + 5x).