Answer:
n = 30
Step-by-step explanation:
since it cost 90 to keep open, the equation needs to equal 90
90 = ?
because it cost 13 for a book and x equals the amount of books
90 = -13x
because you make 16 for each book
90 = -13x + 16x
now you can simply
90 = 3x
x = 30
so the answer is 30
<u>Step-by-step explanation:</u>
the answer should $201.25