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如何证明:44...44(2n个)-88...88(n个) 是个平方数

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/06/05 05:43:23
如何证明:44...44(2n个)-88...88(n个) 是个平方数
44...44(2n个)-88...88(n个)
=4×(111.1(2n个)-2×11...1(n个))
=4×(111.1000...000(n个1n个0)-2×11...1(n个))
=4×111.1 (n个) 再答: 44...44(2n个)-88...88(n个) =4×(111.....1(2n个)-2×11...1(n个)) =4×(111.....1000...000(n个1n个0)-2×11...1(n个)) =4×111....1 (n个)×(1000...0 (n个)-2) =4×111....1 (n个)×99....9(n个) =36×111....1 (n个)×111....1 (n个) =6²×111....1 (n个)² =66....6²