Date: Oct 4, 2012 3:31 PM Author: lenusv44 Subject: I need to demonstrate that 3^80 -2^20 is divisible by 5 . hint u(3^80)=1 Hi ,

would you be so kind to help me with the maths problem , please ?

I need to demonstrate that 3^80 -2^20 is divisible by 5 .

I have this hint u(3^80)=1 but I don't get it .

Thank you

kind regards