r2-r1-r2,r1-2r3
0 3 1
0 1 3
1 -1 0
r1-3r2,r3+r2
0 0 -8
0 1 3
1 0 3
r1*(-1/8),r2-3r1,r3-3r1
0 0 1
0 1 0
1 0 0
r1r3
1 0 0
0 1 0
0 0 1