Have you heard of an integral? Well anyway, we're looking for the anti-derivative of
In order to get an the power rule tells us we need an but the derivative of so we'd have a 4 out in front when we want a 20, so let's put a 5 out in front of our original guess
Now the derivative of so the first term is done....
Doing similar steps will lead you to an answer of
Note that when we take the derivative of that, the +c has a derivative of zero, since the question is to find an antiderivative, you can choose any value for c as the answer