A bookstore is deciding what price it should charge for a certain book. After research, the store finds that if the book's price is p dollars (where p is less than or equal to 26), then the number of books sold per month is 130-5p. What price should the store charge to maximize its revenue?
If the number of books sold = 130-5p then revenue will be (130-5p)p = -5p^2+130p
the maximum can be found by graphing or by the fact that the max will be -b/2a = -130/-10 = 13 dollars/book
[130-5(13)] (13) = $845 max revenue.