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.

After reading through the story problem, I ended up with this equation:

(35-2)(x+.5) =?

or

(35-2)(10+.5)=?

Explanation:

He sells 35 books for usual weeks. Since he is selling his books at $.50 more his average number of copies decreased by 2.

35-2 = 33

Next, we know that he adds $.50 for his price for each copy. If the price is $10 per copy than it looks like this:

$10+$.50= 10+.5

or if the price is not $10 it will be

$x+$.5= x+.5

y = -x^2 − 2.5x + 350

Step-by-step explanation:

y = (10 + 0.5x)(35 − 2x)

y = 350 − 20x + 17.5x − x^2

y = 350 − 2.5x − x^2