Use rise over run to find slope. If you don't know what that is, its y2-y1/x2-x1. Y2 is 125, Y1 is 25, X2 is 5, and X1 is 1. You then plug the numbers in, 125-25=100. 5-1=4. then you divide 100/4, in which you get 25. So you times 25 by 3, getting 75.
2p+6a=$14
3p+9a=$21
3p+9a=21
Subtract 9a
3p=21-9a
divide all by 3
p=7-3a
plug it into start equations
2p+6a=14
2(7-3a)+6a=14
14-6a....+6a=14
this zeroes out...
First you have to set up your equation. 5x+80 and x+15.
