判断下面数列是否是等差数列 ﹙1﹚2,4,6,8····2﹙n-1﹚,2n,··· ﹙2﹚1,1,2,3,4·····﹙3﹚a,a,a,·····a···2已知数列-5,-3,-1,1····是等差数列,判断52,2n+7﹙n∈N*﹚是否是等差数列的项.若是,是第几项3若m和2n等差中项为4,2m和n的等差中项为5,则m和n的等差中项是
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判断下面数列是否是等差数列 ﹙1﹚2,4,6,8····2﹙n-1﹚,2n,··· ﹙2﹚1,1,2,3,4·····
﹙3﹚a,a,a,·····a···
2已知数列-5,-3,-1,1····是等差数列,判断52,2n+7﹙n∈N*﹚是否是等差数列的项.若是,是第几项
3若m和2n等差中项为4,2m和n的等差中项为5,则m和n的等差中项是
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