It's a y=mx+b equation, Carries' would be y=1/2 x - 125 (total profit is equal to the cupcake amount, each sold for 50 cents - the startup cost of 125). Juanita's would be y=2.25x-125. Comparing Carries' to Juanita's sales would mean that you would multiply x by 3 (no less than 3 times the ..). I may elaborate further on comparing in the comment section