Remove as a 'common factor' and see that the thing inside the brackets is a perfect derivative.
Alternatively, use the integrating factor technique used for solving some first order ode's.
I'm trying to remember how to solve a type of equation I've reduced a second order partial differential to.
In the notes it goes from the equation:
With subscripts denoting partial derivatives.
I know that these two steps are equivalent, I'm just wondering on what the procedure used is to get the second equivalent form.
If the procedure has a name which I can look up.
Any assistance would be greatly appreciated, thank you.