Question

Hamid published a book of poems. He sold 35 copies in the first week for $10 per copy. He wanted to increase the price of

each book to increase his revenue. He found out that for every 50-cent increase, x, in the price per copy, the average number
of books he sold decreased by 2 per week.
Assuming that Hamid's revenue is found by multiplying the book price by the number of copies sold, create an equation in
standard form) to model his revenue.
Type the correct answer in the box.

Answer 1

Answer: y=-x^2-2.5x+350

Explanation:

First determine the expression that models the number of copies sold. Hamid initially sold 35 copies when the price was $10, but the number of copies sold each week decreases by 2 with each 50-cent increase in price. So, represent the number of copies sold like this:

number of copies sold = 35 − 2x

Next, determine the expression that models the book price. The initial price is $10, and Hamid is increasing the book price in 50-cent increments. So, represent the book price like this:

book price = 10 + 0.50x

revenue = (book price)(number of copies sold)

y = (10 + 0.5x)(35 − 2x)

y = 350 − 20x + 17.5x − x2

y = 350 − 2.5x − x2

y = -x2 − 2.5x + 350

Answer 2

Answer:y = -x2 − 2.5x + 350

Explanation:

revenue = book price number of copies sold

y = (10 + 0.5x)(35 − 2x)

y = 350 − 20x + 17.5x − x2

y = 350 − 2.5x − x2

y = -x2 − 2.5x + 350