[tex]Criteriul\ de\ divizibilitate\ cu\ 5:\\
Un\ numar\ este\ divizibil\ cu\ 5\ daca\ ultima\ cifra\ este\ 0\ sau\ 5\\
U(6^{2013})=U(6^{2013*1})=U(6^{1})=U(6)=6\\
U(3^{2012})=U(3^{503*4})=U(3^{4})=U(81)=1\\
U(6^{2013}-3^{2012})=U(6-1)=U(5)=5\\C\ este\ divizibil \ cu\ 5.[/tex]