\[ \begin{split} &\lim_{n \to \infty} \left(\frac{n+5}{n}\right)^n=\\[16pt] &=\lim_{n \to \infty} \left(1+\frac{5}{n}\right)^n=\\[16pt] &=\lim_{n \to \infty}\left(1+\frac{1}{\frac{n}{5}}\right)^n=\\[16pt] &=\lim_{n \to \infty} \left[\left(1+\frac{1}{\frac{n}{5}}\right)^\dfrac{n}{5}\right]^5=\\[16pt] &=e^5 \end{split} \]