1-2r2,r3-3r2,r4-2r2
0 -1 1 1 1
1 2 0 -2 -4
0 -8 8 9 12
0 -7 7 8 11
r1*(-1),r2-2r1,r3+8r1,r4+7r1
0 1 -1 -1 -1
1 0 2 0 -2
0 0 0 1 4
0 0 0 1 4
r1+r3,r4-r3
0 1 -1 0 3
1 0 2 0 -2
0 0 0 1 4
0 0 0 0 0
r1r2
1 0 2 0 -2
0 1 -1 0 3
0 0 0 1 4
0 0 0 0 0
此为行最简形.(不知道你教材上"最简阶梯形"是怎么定义的)
++++++++++++++++++++++++++++
(A,E) =
3 -2 0 -1 1 0 0 0
0 2 2 1 0 1 0 0
1 -2 -3 -2 0 0 1 0
0 1 2 1 0 0 0 1
r1-3r3
0 4 9 5 1 0 -3 0
0 2 2 1 0 1 0 0
1 -2 -3 -2 0 0 1 0
0 1 2 1 0 0 0 1
r1-4r4,r2-2r4,r3+2r4
0 0 1 1 1 0 -3 -4
0 0 -2 -1 0 1 0 -2
1 0 1 0 0 0 1 2
0 1 2 1 0 0 0 1
r2+2r1,r3-r1,r4-2r1
0 0 1 1 1 0 -3 -4
0 0 0 1 2 1 -6 -10
1 0 0 -1 -1 0 4 6
0 1 0 -1 -2 0 6 9
r1-r2,r3+r2,r4+r2
0 0 1 0 -1 -1 3 6
0 0 0 1 2 1 -6 -10
1 0 0 0 1 1 -2 -4
0 1 0 0 0 1 0 -1
交换行
1 0 0 0 1 1 -2 -4
0 1 0 0 0 1 0 -1
0 0 1 0 -1 -1 3 6
0 0 0 1 2 1 -6 -10
得 A^-1 =
1 1 -2 -4
0 1 0 -1
-1 -1 3 6
2 1 -6 -10