# How do you multiply -7(3x + 7) + 4?

Jun 20, 2016

$- 7 \left(3 x + 7\right) + 4 = - \textcolor{g r e e n}{21 x - 45}$

#### Explanation:

Using the distributive property for multiplication over addition:
$\textcolor{red}{- 7} \left(\textcolor{b l u e}{3 x} + \textcolor{p u r p \le}{7}\right) + \textcolor{c y a n}{4}$
$\textcolor{w h i t e}{\text{XXX}} = \left(\left(\textcolor{red}{- 7}\right) \cdot \left(\textcolor{b l u e}{3 x}\right) + \left(\textcolor{red}{- 7}\right) \cdot \left(\textcolor{p u r p \le}{7}\right)\right) + \textcolor{c y a n}{4}$

$\textcolor{w h i t e}{\text{XXX}} = \left(\textcolor{\mathmr{and} a n \ge}{- 21 x} \textcolor{b r o w n}{- 49}\right) + \textcolor{c y a n}{4}$

$\textcolor{w h i t e}{\text{XXX}} = \textcolor{g r e e n}{- 21 x - 45}$