Solve the System by Using the Inverse of the Coefficient $$\begin{array} { c } 3 x - y - 9 z = - 68 \\- 9 x - 3 z = - 30 \\2 y + z = 23\end{array}$$

Multiple Choice

Solve the system by using the inverse of the coefficient matrix.
- $$\begin{array} { c } 3 x - y - 9 z = - 68 \\- 9 x - 3 z = - 30 \\2 y + z = 23\end{array}$$

A) $\{ ( 1,7,8 ) \}$
B) $\varnothing$
C) $\{ ( 1,8,7 ) \}$
D) $\{ ( - 1,8,2 ) \}$