You have to use the y2-y1 over x2-x1. So, let's plug the numbers in. (-3,-3) ^ ^ X1 Y1 (4,0) ^ ^ X2 Y2 So, that would be 0-(-3) —— 4-(-3) The two subtraction signs counteract and become a positive, or addition symbol. So it would be 0+3 —— 4+ 3 Do the addition to get 3 over 7 or 3 — 7