# How do you simplify  (-9x^2 - 4x - 4) - (-9x^2 - 11x + 12)?

##### 1 Answer
Jun 18, 2015

 =color(blue)(7x -16

#### Explanation:

$\left(- 9 {x}^{2} - 4 x - 4\right) - \left(- 9 {x}^{2} - 11 x + 12\right)$

$= - 9 {x}^{2} - 4 x - 4 + 9 {x}^{2} + 11 x - 12$

Grouping like terms:
$= \textcolor{red}{\left(- 9 {x}^{2} + 9 {x}^{2}\right)} + \textcolor{b l u e}{\left(- 4 x + 11 x\right)} - 4 - 12$
$= 0 + \textcolor{b l u e}{7 x} - 16$
 =color(blue)(7x -16