2 -1 -1 1 2
1 1 -2 1 4
4 -6 2 -2 4
3 6 -9 7 9
r1-2r2,r3-4r2,r4-3r2 得
0 -3 3 -1 -6
1 1 -2 1 4
0 -10 10 -6 -12
0 3 -3 4 -3
r1+r4,r3+3r4
0 0 0 3 -9
1 1 -2 1 4
0 -1 1 6 -21
0 3 -3 4 -3
r2+r3,r4+3r3,r1*(1/3)
0 0 0 1 -3
1 0 -1 7 -17
0 -1 1 6 -21
0 0 0 22 -66
r2-7r1,r3-6r1,r4-22r1
0 0 0 1 -3
1 0 -1 0 4
0 -1 1 0 -3
0 0 0 0 0
r3*(-1),交换一下行即得
1 0 -1 0 4
0 1 -1 0 3
0 0 0 1 -3
0 0 0 0 0
有不明之处可参考一下我的这个回答: