Copy Cats charges a $21 surcharge for a batch of colored copies plus $0.15 per page. Heritage Printing charges a $25.50 surcharge for a batch of colored copies plus $0.12 per page. How many pages of colored copies would make Heritage Printing cheaper than Copy Cats?

If x is the number of pages printed, you need

25.50 + .12x < 21.00 + .15x
4.50 < .03x
150 < x

so, anything over 150 pages is cheaper at Heritage