【急求】初等变换求逆矩阵123221343r3-r1-r2,我们教材都没有.

解: (A,E) =
1 2 3 1 0 0
2 2 1 0 1 0
3 4 3 0 0 1
r3-r1-r2,r2-2r1
1 2 3 1 0 0
0 -2 -5 -2 1 0
0 0 -1 -1 -1 1
r3*(-1),r1-3r3,r2+5r3
1 2 0 -2 -3 3
0 -2 0 3 6 -5
0 0 1 1 1 -1
r1+r2,r2*(-1/2)
1 0 0 1 3 -2
0 1 0 -3/2 -3 5/2
0 0 1 1 1 -1
所以 A^-1 =
1 3 -2
-3/2 -3 5/2
1 1 -1