解: 增广矩阵=1 1 2 1 22 3 7 5 55 6 13 8 11r2-2r1,r3-3r11 1 2 1 20 1 3 3 10 1 3 3 1r1-r2,r3-r21 0 -1 -2 10 1 3 3 10 0 0 0 0方程组的通解为 (1,1,0,0)^T+c1(1,-2,1,0)^T+c2(2,-3,0,1)^T
