 So far we have found out how we get to equations 1, 2, 3 and 4 by just looking at the VT graph. For number 5, we actually can't look directly at the VT graph, but we can find it by combining number 1 and number 2. How do we do that? First we take number 1 which is V final is V initial plus a times delta t. We take refinal over and divide by a and therefore we know the change in time is final velocity minus initial velocity over acceleration. Equation number 2 was the change in position was 1 half final velocity plus initial velocity which was the average velocity times delta t. Now we put whatever we have here in that delta t, therefore we have delta s is 1 half refinal plus initial times refinal minus initial divided by acceleration. We multiply that by 2 and by a we get 2a delta s is refinal plus initial times refinal minus initial. If we multiply that out we get refinal square minus refinal times initial plus refinal times refinal times refinal minus initial square. These two times literally out, therefore we get refinal is, if we take the refinal over on that side, refinal square plus 2a delta s which is exactly our fifth formula.