52•32n+1•2n-3n•6n+2能被13整除吗?

问题描述:

52•32n+1•2n-3n•6n+2能被13整除吗?

52•32n+1•2n-3n•6n+2能被13整除.理由如下:
∵52•32n+1•2n-3n•6n+2
=52•(32n•3)•2n-3n•(6n•62
=75•32n•2n-36•3n•6n
=75•18n-36•18n
=39•18n
=13×3•18n
又∵3•18n是整数,
∴52•32n+1•2n-3n•6n+2能被13整除.