Answer: they have to sell 880 books to break even.
Explanation:
Let x represent the total number of books that Richmond high school produced and also sold.
Richmond high school is paying $13,200 for the writing and research of their yearbook plus a printing fee of $25 per book. This means that the total cost of producing x books would be
25x + 13200
if they sell the books at $40 each, it means that the total revenue would be
40 × x = 40x
The break even point is the point at which income equals expenses expenses. Therefore,
25x + 13200 = 40x
40x - 25x = 13200
15x = 13200
x = 13200/15
x = 880