I have an example ofPartial Fractions decomposition, but cant understand it.

Here we have

And whats goes next, Itotallydon't get

x^3

x^2

x^1

x^0

; ; ;

So could anyone explain me that most imprtant part?

Now that I think more, it seems that I posted it on wrong section. It's just that later that fromula will be integrated, so it should be known in calculus.

Seems I used wrong name for this method