Ofer 50 de puncte. Cum se rezolva?

[tex]\it \dfrac{3^n+5^n}{3^{n+1}+5^{n+1}}=\dfrac{3^n+5^n}{3\cdot3^{n}+5\cdot5^{n}}=\dfrac{\Big(\dfrac{3}{5}\Big)^n+1}{3\cdot\Big(\dfrac{3}{5}\Big)^n+5} \stackrel{n\rightarrow \infty}{\longrightarrow} \dfrac{0+1}{0+5}=\dfrac{1}{5}[/tex]