It is probably a really easy question but i am a bit rusty.
I would like basically to decompose :
I thus need to breakdown into simple elements:
Now I can't remember how to find out A, B and C.
I've already checked online and I understood that, for example to find B:
I should multiply the first fraction (1) by and then change x for -1. but if i do that it will cancel everything.
on the other hand, I can't understand how to find A.
Pretty sure it is quiet basic question but does anyone could explain me the method for this fraction.
Thanks in advance.