Please help! I don't understand this.

Aschool typically sells 500 yearbooks each year for 50 dollars each. the economic calls does a project and discovers that they can sell 100 more yearbooks for every $5 decrease in price. the revenue for yearbook sales is equal to the number of yearbooks sold times the price of the yearbook. let x represent the number of $5 decrease in price. if the expression that represents the revenue is written in the form r(x)=(500+ax)(50-bx). to maximize profit, what price should the school charge for the yearbooks? what is the possible maximum revenue? if the school attains the maximum revenue, how many yearbooks will they sell?

Refer to the table below if needed. second quadrant third quadrant fourth quadrant sin(1800- - cos(180° -) tan(180°-e) =- tane cot(1800-0) 10 it to solo 888 sin(180° +c) = - sine cos(180° +) =- cose tan(180° +c) = tane cot(180° +o) = cote sec(180° + c) = - seco csc(180° +2) = - csce sin(360° -) =- sine cos(360° -) = cose tan(360° - e) =- tane cot(360° -) = -cote sec(360° -) = seco csc(360° -) = csco sec(180° -) = csc(180° -) = csca 1991 given that sine = 3/5 and lies in quadrant ii, find the following value. tane

Problem fathi wants to print out a pdf document that is 48 pages long. to save paper, he decides to print on both sides of each sheet and to print two pages on each side of the sheet. how many sheets of paper will he need?