Question

Afla ultima cifra a numarului a=2016^2017 + 2014^2017 + 2012^2017

Answer 1

^   la   orice   putere   are   ultima  cifra  6=>
U(2016^2017)=6
4  la  o   putere  impara   are ultima   cifra  4=>
U(2014^2017=4
2^1=2 U=2
2^2=4 U=4
2^3=8 U=8
2*4=16 U=6
2^5=32  U(32)=2
=.U(2^4k+1)=2
U(2^2017)=U(2^2016+1)=2
U(a)=U(6+4+2)=U(12)=2