# How do you solve -5x - 4y = -48 and -3x + 2y = 2  using substitution?

Mar 12, 2016

$x = 4$

#### Explanation:

$- 5 x - 4 y = - 48 \text{ (1)}$
$- 3 x + 2 y = 2 \text{ "2y=2+3x " } \textcolor{g r e e n}{2 \cdot} 2 y = \textcolor{g r e e n}{2 \cdot} \left(2 + 3 x\right)$
$\textcolor{red}{4 y = 4 + 6 x}$
$\text{use (1)}$
$- 5 x - \textcolor{red}{\left(4 + 6 x\right)} = - 48$
$- 5 x - 4 - 6 x = - 48$
$- 11 x = - 48 + 4$
$- 11 x = - 44$
$x = \frac{44}{11}$
$x = 4$