Solve the System of Linear Equations Using Matrices $$\left\{ \begin{array} { r r } 2 x - 8 y - z = & - 20 \\x - 7 y + 6 z = & 17 \\6 x + y + z = & 64\end{array} \right.$$

Multiple Choice

Solve the system of linear equations using matrices.
- $$\left\{ \begin{array} { r r } 2 x - 8 y - z = & - 20 \\x - 7 y + 6 z = & 17 \\6 x + y + z = & 64\end{array} \right.$$

A) $( 9,6,4 )$
B) $( - 9,4,18 )$
C) $( 9,4,6 )$
D) $\varnothing$