# How do you simplify 12s - 4t + 7t - 3s?

Jul 8, 2015

$12 s - 4 t + 7 t - 3 s = 9 s + 3 t$
or$\textcolor{w h i t e}{\text{XXXX}}$$\textcolor{w h i t e}{\text{XXXX}}$ $= 3 \left(3 s + t\right)$

#### Explanation:

$12 s - 4 t + 7 t - 3 s$
can be regrouped as
$\textcolor{w h i t e}{\text{XXXX}}$$\left(12 s - 3 s\right) + \left(7 t - 4 t\right)$

$\textcolor{w h i t e}{\text{XXXX}}$$= \left(12 - 3\right) s + \left(7 - 4\right) t$
$\textcolor{w h i t e}{\text{XXXX}}$$= 9 s + 3 t$

or, extracting a common factor of 3
$\textcolor{w h i t e}{\text{XXXX}}$$= 3 \left(3 s + t\right)$