lim (2^n + 5.3^n)/(7.2^n + 3^n) bằng

$\lim \frac{2^{\mathrm{n}}+5{.3}^{\mathrm{n}}}{7{.2}^{\mathrm{n}}+3^{\mathrm{n}}}=\lim \frac{{\left(\frac{2}{3}\right)}^{\mathrm{n}}+5}{7.{\left(\frac{2}{3}\right)}^{\mathrm{n}}+1}=\frac{0+5}{7.0+1}=5.$

Vậy chọn phương án A.