# Simplifying a rational expression

1. Mar 22, 2009

### Kaylee!

I've done a calculus problem. The LHS is my answer and the RHS is the answer in the book.

$$\frac{2(x-1)^2}{(x^2-1)^2} = \frac{2}{(x+1)^2}$$

What was done to simplify this equation?

2. Mar 22, 2009

### rock.freak667

x2-1=(x-1)(x+1)

3. Mar 22, 2009

### Chaos2009

I believe it was called the Difference of Squares. Factor it out and try again.