Solve the linear system LaTeX: \displaystyle \begin{cases} 4 x - 5 y - 6 z = 8 \\ 8 x + 6 y - 4 z = -8 \\ - 9 x + 9 y - 4 z = -162 \\ \end{cases}

The Solution is LaTeX: \displaystyle (8, -6, 9) .