# How do you find the solution of the system of equations -3x + y = -4  and 3x + y = -4?

May 2, 2015

We can add the two equations to eliminate $3$ $x$

Adding the 2 equations will give us:

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

$y - \cancel{3 x} + y + \cancel{3 x} = - 8$

$2 y = - 8$
$\textcolor{b l u e}{y = - 4}$

Substituting this value of $y$ in the second equation we get $x$ :

we are given:
$3 x + y = - 4$

$3 x = - 4 - y$
$3 x = - 4 + 4$
$3 x = 0$

$\textcolor{b l u e}{x = 0}$

The solution to these system of equations is:

color(blue)(x = 0 , y = -4