123 32 00000 000 200 600 00000 000 runk(A)=2<5,所以原方程组有非零解 「x1=x3+x4+5 x2=-2x3-2x4-6X5 同解方程组为 4 xs=x5 K心            → 0 0 0 0 0 0 0 0 0 0 0 1 2 2 6 1 2 3 3 7             − − − → 0 0 0 0 0 0 0 0 0 0 0 1 2 2 6 1 0 1 1 5 rank(A) = 2  5, 所以原方程组有非零解. 同解方程组为          = = = = − − − = + + 5 5 4 4 3 3 2 3 4 5 1 3 4 5 2 2 6 5 x x x x x x x x x x x x x x