1 2 3 4 -1 2 0 1 0 1 0 2..r2<->r3...>1 2 3 4 0 1 0 2-1 2 0 1...r3+r1---->1 2 3 4 0 1 0 20 4 3 5....r3+(-4)r2.....>1 2 3 4 0 1 0 20 0 3 -3=>矩阵的秩=3
你这是四行三列还是几列啊
