Ok, so i do everything to one point and can't get the right answer.

The question is:

By using the substitution y = xu solve:

The answer is:

Now, i differentiate y = xu:

After substituting in and canceling i get:

I then take u to the otherside and put it into the fraction, multiply and integrate to get:

Taking the exponential:

Then i substitute in y = xu ( u = y / x) :

Re-arranging:

Making y the subject does not give the anwser.

Any help would be greatly appriciated. Thank-you