That's a 3x3 linear system. Let's do Gaussian elimination
4 3 1 -10 A
1 -3 2 -8 B
11 -2 3 -38 C
0 15 -7 22 D=A-4B
0 31 -19 50 E=C-11B
0 1 -7/15 22/15 F=D/15
1 0 3/5 -18/5 G=B+3F
0 0 -68/15 68/15 H=E-31F -19-31(-7/15), 50-31(22/15)
0 0 1 -1 I=-15/68 H
1 0 0 -3 J=G - 3/5 I
0 1 0 1 K=F+ 7/15 I
We read off from the last three lines the
Answer: x=-3, y=1, z=-1
