# How do you solve and write the following in interval notation:  (x-4)(x+2)>0?

Jul 15, 2016

$x \notin \left[- 2 , 4\right]$

#### Explanation:

The product > 0. So, the factors are of opposite signs.

If $x - 4 > 0$, then $x + 2 > 0$. These combine to give $x > 4$. .

If $x + 2 < 0$, then $x - 4 < 0$. These combine to give $x < - 2$.

Thus, $x \notin \left[- 2 , 4\right]$