问题描述:(n^k-1)/(n-1)=?求具体推导最佳答案: n^k-1=n^k-n^(k-1)+n^(k-1)-n^(k-2)+n^(k-2)-……-n+n-1=n^(n-1)(n-1)+n^(k-2)(n-1)+……+(n-1)=(n-1)[n^(k-1)+n^(k-2)+……+1]原式=n^(k-1)+n^(k-2)+……+1 点击显示答案