Answer
$x=-4$
$y=5$
Work Step by Step
$$\begin{cases}
x=16-4y\\
3x+4y=8
\end{cases}$$
$x$ is already expressed as a function of $y$ in the first equation, so we substitute it into the second equation to find $y$:
$$3(16-4y)+4y=8$$
$$48-12y+4y=8$$
$$48-8y=8$$
$$-8y=8-48$$
$$-8y=-40$$
$$y=-40:(-8)=5$$
Determine $x$:
$$x=16-4(5)=16-20=-4$$
The solution is:
$$\begin{cases}
x=-4\\
y=5
\end{cases}$$
