I would like to start out by saying that I am completely against making u substutions for all integrals...
Mr F asks with incredulity: ALL ......??!
I would much rather recognize a pattern, guess at an antiderivative, and then put a correction factor out in front (I know most universities don't teach it like this, but let's give it a shot)
We know the integral of
is
So let's "guess" that the integral is
Now if we take the derivative of that, we get
, so we're off by a factor of 5, so let's put
in front of our "guess" and we'll be good
So the answer is