б) $$ \frac{3^{n+2}+5 \cdot 3^n}{3^n} = \frac{3^n \cdot 3^2 + 5 \cdot 3^n}{3^n} = \frac{3^n(3^2+5)}{3^n} = 3^2+5 = 9+5 = 14 $$
Ответ: $$14$$