Solve the System of Equations Using Matrices $5 \mathrm{x}-\mathrm{y}-6 \mathrm{z}=-9$ $4 \mathrm{x}+9 \mathrm{z}=69$

Multiple Choice

Solve the system of equations using matrices.
- $5 \mathrm{x}-\mathrm{y}-6 \mathrm{z}=-9$
$4 \mathrm{x}+9 \mathrm{z}=69$
$7 y+z=68$

A) $(6,9,5)$
B) $(6,5,9)$
C) $(-6,5,9)$
D) $(-6,9,12)$