Solve the linear system LaTeX: \displaystyle \begin{cases} - 8 x + 6 y - 9 z = 84 \\ 9 x + 6 y + z = 2 \\ - 2 x - 5 y - 9 z = -51 \\ \end{cases}

The Solution is LaTeX: \displaystyle (-6, 9, 2) .