系数矩阵 A=
2 -1 3
1 -3 4
-1 2 3
r1-2r2,r3+r2
0 5 -5
1 -3 4
0 -1 7
r1*(1/5),r2+3r1,r3+r1
0 1 1
1 0 7
0 0 8
r(A) = 3,所以方程组只有零解.