How do you solve the following linear system: 4x-y=-4 , 3x+3y=-18 ?

Jun 21, 2018

$x = - 2$ and $y = - 4$

Explanation:

$3 \cdot \left(4 x - y\right) + 3 x + 3 y = 3 \cdot \left(- 4\right) + \left(- 18\right)$

$12 x - 3 y + 3 x + 3 y = \left(- 12\right) + \left(- 18\right)$

$15 x = - 30$, so $x = - 2$

Hence,

$4 \cdot \left(- 2\right) - y = - 4$

$- 8 - y = - 4$

$y = \left(- 8\right) - \left(- 4\right) = - 4$