Question

Mike and Kim invest $12,000 in equipment to print yearbooks for schools. Each yearbook costs $5 to print and sells for $15. How many yearbooks must they sell before their business breaks even?

Answer 1

First of all, you sell one book for 15$ and you use 5$ to print it which mean, the revenue is 10$.
To find the number of books could be sold with 12,000$. Take 12,000 and divide by 10 and you will get 1200 books.
Hope this answered your question :)

Answer 2

12000+5x=15x
12000=10x
1200=x

They must sell 1200 yearbooks.