I'm very new to this form of solving differential equations and I've come to a stump in a problem.
The problem is simply to find the general solution to
I have a guide that also shows the steps to the solution, but the area I am stuck on is identical to the guide, where i don't see how it got from one step to the next.
This is what I have so far;
Now, at this point I assumed it would be very easy to separate the variables to;
And solve by integration. However, the guide goes from
My question is... what step am i missing that u becomes 2u and 4/x becomes 8/x?
Thanks for your time