Break rational expression into Partiall fractions

[gammonsmurf (peter B)]

If I have I want to integrate

(a) 1/(2 + 3 x + x^2)

I know that by algorithm you can write this as,

(b) 1/(1 + x) - 1/(2 + x)

but are that a command for matematica so create separate fractions?

to go from (b) to (a)

[nma (Nasser M. Abbasi)]

it is called Apart to go “back” use Simplify