Solve the linear system LaTeX: \displaystyle \begin{cases} - 4 x - y + 8 z = 40 \\ - 3 x + 4 y + 7 z = 51 \\ - x + 7 y + 3 z = 41 \\ \end{cases}

The Solution is LaTeX: \displaystyle (-7, 4, 2) .