Solve Systems of Linear Equations in Three Variables
- $$\begin{array} { c } x + y + z = - 7 \\x - y + 3 z = - 13 \\2 x + y + z = - 9\end{array}$$

Multiple Choice

Solve Systems of Linear Equations in Three Variables
- $$\begin{array} { c } x + y + z = - 7 \\x - y + 3 z = - 13 \\2 x + y + z = - 9\end{array}$$

A) $\{ ( - 2 , - 1 , - 4 ) \}$
B) $\{ ( - 1 , - 2 , - 4 ) \}$
C) $\{ ( - 4 , - 1 , - 2 ) \}$
D) $\{ ( - 4 , - 2 , - 1 ) \}$