Use Cramer's rule to find xxx in the system: {2x+y−z=5x−y+2z=1x+2y+z=4\begin{cases} 2x + y - z = 5 \\ x - y + 2z = 1 \\ x + 2y + z = 4 \end{cases}⎩⎨⎧2x+y−z=5x−y+2z=1x+2y+z=4
222
−2-2−2
111
333