Question

3.设A＝1 1 -1 0 2 2 1 -1 0,B＝1 -1 0 1 1 0 2 1 1 .求矩阵方程XA＝B的解.

Answer 1

解: 构造分块矩阵(上下两块)
A
B
1 1 -1
0 2 2
1 -1 0
-------
1 -1 0
1 1 0
2 1 1
c2-c1,c3+c1
1 0 0
0 2 2
1 -2 1
1 -2 1
1 0 1
2 -1 3
c3-c2
1 0 0
0 2 0
1 -2 3
1 -2 3
1 0 1
2 -1 4
c2*(1/2),c3*(1/3)
1 0 0
0 1 0
1 -1 1
1 -1 1
1 0 1/3
2 -1/2 4/3
c1-c3,c2+c3
1 0 0
0 1 0
0 0 1
----------
0 0 1
2/3 1/3 1/3
2/3 5/6 4/3
所以 X=
0 0 1
2/3 1/3 1/3
2/3 5/6 4/3
满意请采纳^_^