In order to solve this problem you would put it into the formula y=mx+b. So, it would be 2y=-5x+8. After that you would divide both sides by 2. you would get y=-5/2x+8/2. and to find the perpendicular you would take the M in the formula which is -5/2 flip it so you would get -2/5. Finally you switch the sign and get 2/5 as your final answer.
