设A=(aij)n×n是n阶可逆矩阵，且A的每行元素之和均为常数c，则A-1的每行元素之和为______．
参考答案：[*]
解析：
[分析]： 因为A的每行元素之和均为常数c，即有ai1+ai2+…+ain=c(i=1，2，…，n)，从而因为A可逆，所以c≠0(否则若c=0，上式左乘A-1即得(1，1，…，1)T=(0，0，…，0)T，矛盾)．上式左乘A-1可得
[*]
故A-1的每行元素之和为[*]．
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