系数矩阵A=1 2 0 -1-1 1 -3 22 -1 5 -3r2+r1,r3-2r11 2 0 -10 3 -3 10 -5 5 -1r3+(5/3)r21 2 0 -10 3 -3 10 0 0 2/3r3*(3/2),r1+r3,r2-r31 2 0 00 3 -3 00 0 0 1r2*(1/3),r1-2r21 0 2 00 1 -1 00 0 0 1所以方程组的一般解为:c(-2,1,1,0)^T,c为任意常数.