Question

aratati ca numarul n=2^59+7^61 este divizibil cu 5​

Answer 1

$\it u(2^{59})=u(2^{56+3})=8\\ \\ u(7^{61})=u(7^{60+1})=7\\ \\ u(2^{59})+u(7^{61})=u(8+7)=u(15)=5 \Rightarrow (2^{59}+7^{61})\ \vdots\ 5$