# How do you simplify (r^3-7r )/( r^2 - 4)?

Jul 27, 2017

This expression does not simplify ...

#### Explanation:

You might be temped to cancel - but you may not because of the minus signs. Factorise as far as possible.

$\frac{{r}^{3} - 7 r}{{r}^{2} - 4} \text{ "(larr"common factor")/(larr"difference of squares}$

$= \frac{r \left({r}^{2} - 7\right)}{\left(r + 2\right) \left(r - 2\right)}$

This expression does not simplify ...