# Thread: Systems in 3 Variables

1. ## Systems in 3 Variables

Have to find x,y,and z.

1.)
x - y - 5z = -2
y + 3z = 9
x + y + z = 16

2. Solve this

$\left[ \begin{array}{c}
x\\
y\\
z\end{array}\right]=\left[ \begin{array}{ccc}
1 & -1 & -5 \\
0 & 1 & 3 \\
1 & 1 & 1 \end{array} \right]^{-1} \left[ \begin{array}{c}
-2\\
9\\
16\end{array}\right]$