第十五届“希望杯”全国数学邀请赛初一第2试If n is a positive integer, and if the units'digit of n2 is 6 and the units' digit of (n-1)2 is 9, the units' digit of (n+1)2 is _____. (英汉小词典units' digit;个位数字)

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第十五届“希望杯”全国数学邀请赛初一第2试If n is a positive integer, and if the units'digit of n2 is 6 and the units' digit of (n-1)2 is 9, the units' digit of (n+1)2 is _____. (英汉小词典units' digit;个位数字)
第十五届“希望杯”全国数学邀请赛初一第2试
If n is a positive integer, and if the units'digit of n2 is 6 and the units' digit of (n-1)2 is 9, the units' digit of (n+1)2 is _____.
(英汉小词典units' digit;个位数字)

第十五届“希望杯”全国数学邀请赛初一第2试If n is a positive integer, and if the units'digit of n2 is 6 and the units' digit of (n-1)2 is 9, the units' digit of (n+1)2 is _____. (英汉小词典units' digit;个位数字)
个位数为0到9的数的平方的个位数为:
0----0
1----1
2----4
3----9
4----6
5----5
6----6
7----9
8----4
9----1
由此可知n的个位数是4,n+1的个位数为5,(n+1)^2的个位数为5.