求逆矩阵为什么不能用行列混合变换呢？？？？ 初等变换求逆矩阵时能不能同时使用初等列变换和初等行变换
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列相当于右乘
所谓混合变换不是绝对不能用，看你要干什么了
比如解线性方程组，相当于左乘系数矩阵的逆，那当然不能乱变
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