Solve the System $$\left( \begin{array} { c } 4 x + 7 y - 7 z = 22 \\2 x - 2 y + 6 z = - 12 \\5 x - 4 y + 7 z = - 7\end{array} \right)$$

Solve the system. $$\left( \begin{array} { c } 4 x + 7 y - 7 z = 22 \\2 x - 2 y + 6 z = - 12 \\5 x - 4 y + 7 z = - 7\end{array} \right)$$