2(3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)(3^32+1)+1的个位数字为（ ） A.1 B.3 C.7 D.9
2(3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)(3^32+1)+1的个位数字为（ ） A.1 B.3 C.7 D.9
日期：2014-04-12 20:44:39 人气：1
2(3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)(3^32+1)+1
=(3-1)(3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)(3^32+1)+1
=(3^2-1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)(3^32+1)+1
=(3^4-1)(3^4+1)(3^8+1)(3^16+1)(3^32+1)+1
=(3^64-1)+1
=3^64
3^4=81个位是1
因此3^64个位是1