增广矩阵 =
1 1 1 6
2 -1 3 9
2 3 -2 2
r2-2r1,r3-2r1
1 1 1 6
0 -3 1 -3
0 1 -4 -10
r1-r3,r2+3r3
1 0 5 16
0 0 -11 -33
0 1 -4 -10
r2*(-1/11),r1-5r2,r3+4r2
1 0 0 1
0 0 1 3
0 1 0 2
所以 X=(1,2,3)^T.