[Algebra] How does this equal that?

I'm in a Discrete Math class and I'm stuck on the algebra (I know, right?). I simply don't know how the first line equals the second:

1. 1 + [ (x^2 (1 + x) ) / (1 - x)^3 ]

2. (4x^2 - 3x + 1) / (1 - x)^3

Your help is appreciated!