(3a^n+1+6a^n+2-9a^n)/3a^n-1是计算题

问题描述:

(3a^n+1+6a^n+2-9a^n)/3a^n-1是计算题

(3a^n+1+6a^n+2-9a^n)/3a^n-1
=1/(3a^n)-1
=(1-3a^n)/(3a^n)