Question

The cost in dollars to print n books is 500 + 10n. How many books are printed for a cost of $15 000?

Answer 1

N= the # of books
So you're trying to find n and you have the cost for the printed books, which is 15,000, so you would set up your equation like this:
15,000=500+10n 
Subtract 500 from each side
14850=10n 
Divide by 10
n=1,485 books are printed