1+r2,r4+2r2
0 2 4
-1 0 1
0 2 -3
0 1 6
r1-r3,r3-2r4
0 0 7
-1 0 1
0 0 -15
0 1 6
r1*(1/7),r2-r1,r3+15r1,r4-6r1
0 0 1
-1 0 0
0 0 0
0 1 0
r2*(-1),交换行
1 0 0
0 1 0
0 0 1
0 0 0
1+r2,r4+2r2
0 2 4
-1 0 1
0 2 -3
0 1 6
r1-r3,r3-2r4
0 0 7
-1 0 1
0 0 -15
0 1 6
r1*(1/7),r2-r1,r3+15r1,r4-6r1
0 0 1
-1 0 0
0 0 0
0 1 0
r2*(-1),交换行
1 0 0
0 1 0
0 0 1
0 0 0