Simplify $\frac{x^3-x}{x^2+xy+x+y}$ $$\frac{x^3-x}{x^2+xy+x+y}$$
What I did:
 $$\frac{x}{xy+x+y}$$
through simplifying the $x$'s.
But it's not right.  
What did I do wrong?

$$
\frac{x^3 - x}{x^2 +xy + x +y }
= \frac{x(x^2 - 1)}{x( x+y) + 1( x +y )}
= \frac{x(x - 1)(x+1)}{(x+1)( x+y)}
= \frac{x(x - 1)}{( x+y)}
$$
Here you had to remember that $x^2 -1 = (x+1)(x-1)$. The last step assumes $x\neq -1$.
