​Solve the System of Linear Equations​ $$\left\{ \begin{array} { l l } 7 x + 7 y + 7 z & = 0 \\21 x + 35 y + 28 z & = 6 \\21 x + 42 y + 35 z & = 1\end{array} \right.$$

Multiple Choice

​Solve the system of linear equations​ $$\left\{ \begin{array} { l l } 7 x + 7 y + 7 z & = 0 \\21 x + 35 y + 28 z & = 6 \\21 x + 42 y + 35 z & = 1\end{array} \right.$$ ​using the inverse matrix $$\frac { 1 } { 7 } \left[ \begin{array} { c c c } 1 & 1 & - 1 \\- 3 & 2 & - 1 \\3 & - 3 & 2\end{array} \right]$$ .

A) ​ $$\left[ \begin{array} { l } x \\y \\z\end{array} \right] = \left[ \begin{array} { c } \frac { - 5 } { 7 } \\\\\frac { 11 } { 7 } \\\\\frac { - 12 } { 7 }\end{array} \right]$$
B) ​ $$\left[ \begin{array} { l } x \\y \\z\end{array} \right] = \left[ \begin{array} { c } \frac { 5 } { 7 } \\\\\frac { 11 } { 7 } \\\\\frac { - 16 } { 7 }\end{array} \right]$$
C) ​ $$\left[ \begin{array} { l } x \\y \\z\end{array} \right] = \left[ \begin{array} { c } \frac { 16 } { 7 } \\\\\frac { 5 } { 7 } \\\\\frac { 11 } { 7 }\end{array} \right]$$
D) ​ $$\left[ \begin{array} { l } x \\y \\z\end{array} \right] = \left[ \begin{array} { c } \frac { - 12 } { 7 } \\\\\frac { 11 } { 7 } \\\\\frac { - 5 } { 7 }\end{array} \right]$$
E) ​ $$\left[ \begin{array} { l } x \\y \\z\end{array} \right] = \left[ \begin{array} { c } \frac { - 5 } { 7 } \\\\\frac { - 16 } { 7 } \\\\\frac { 11 } { 7 }\end{array} \right]$$