Solve the linear system LaTeX: \displaystyle \begin{cases} x + y + 3 z = -14 \\ - 3 x - 2 y + 6 z = -51 \\ - 4 x - 6 y + 8 z = -58 \\ \end{cases}

The Solution is LaTeX: \displaystyle (7, -3, -6) .