解:因为AX+B=X,所以(A-E)X=-B.
(A-E,B)=
-1101-1
-10120
-1025-3
r3-2r2
-1101-1
-10120
1001-3
r1+r3,r2+r3
0102-4
0013-3
1001-3
交换行
1001-3
0102-4
0013-3
所以X=
-13
-24
-33
解:因为AX+B=X,所以(A-E)X=-B.(A-E,-B)=-110-11-101-20-10-2-53r3+2r2-110-11-101-20-300-93r3*(-1/3),r1+r3,r2+r3010200011-11003-1交换行1003-1010200011-1所以X=3-1201-1