Solve the linear system LaTeX: \displaystyle \begin{cases} - 3 x - 6 y - 4 z = -13 \\ 3 x - 2 y - 9 z = -46 \\ - 7 x - 3 y + 5 z = 26 \\ \end{cases}

The Solution is LaTeX: \displaystyle (3, -4, 7) .