Tìm lim ((4^(n+1) +6^(n+2))/(5^n + 8^n

* Hướng dẫn giải

$$\begin{gathered} \lim \frac{4^{n+1}+6^{n+2}}{5^n+8^n}=\lim \frac{{4.4}^n+36.6^n}{5^n+8^n} \\ =\lim \frac{4.{\left(\frac{4}{8}\right)}^n+36.{\left(\frac{6}{8}\right)}^n}{{\left(\frac{5}{8}\right)}^n+1}=\frac{4.0+\text{}36.0}{0+\text{}1}=0 \end{gathered}$$

Chọn đáp án A