# How do you solve the following system: -5x − y = 14 , y + 4x = 16 ?

Apr 17, 2018

$x = - 30 , y = 136$

#### Explanation:

You have to substitute the $y$ in one equation for the one in the other equation:

$- 5 x - y = 14$

$y + 4 x = 16 \implies y = - 4 x + 16$

So

$- 5 x - \left(- 4 x + 16\right) = 14$

$- 1 x - 16 = 14$

$- 1 x = 30$

$x = - 30$

Now you can plug in the $x$ you found to either equation to find the $y$.

$- 5 \left(- 30\right) - y = 14$

$150 - y = 14$

$y = 136$