系数矩阵 A=
1 -1 0 2 1
3 -3 0 7 0
1 -1 2 3 2
2 -2 2 7 -3
r2-3r1,r3-r1,r4-2r1
1 -1 0 2 1
0 0 0 1 -3
0 0 2 1 1
0 0 2 3 -5
r1-2r2,r3-r2,r4-3r2
1 -1 0 0 7
0 0 0 1 -3
0 0 2 0 4
0 0 2 0 4
-->
1 -1 0 0 7
0 0 1 0 2
0 0 0 1 -3
0 0 0 0 0
方程组的通解为:c1(1,1,0,0,0)' + c2(-7,0,-2,3,1)'.