Use the first two equations to solve for $x$ and $y$ using the Elimination Method.

$−2\left(x + 2y\right) = −2\left(4\right)$

$2x − y = −7$

Now that you know $x$ and $y$, how can you find $z$?

$x = −2$, $y = 3$, $z = −5$