You use a system of equations x= coffee y= donuts x+y=100 3x+y=180 there’s 3 ways to solve system of equations substitution graphing and elimination. it would be easiest to use substitution here. So you multiply x+y=100 by -1 so it become -x-y=-100. then you combine it with the other equation and get 2x=80 so x=40 which means 40 cups of coffee were sold then you plug it back in to find y. 40+y=100. y=60. y= 60 (donuts). x= 40 (coffee)
if you start at (0,0) and go up one and then right on the line lines up with the squares so since slope is you go up one and the right one which makes it so the answer is one.
