Tính giới hạn lim n → + ∞ (5.2^( n + 2) − 2.3^( n + 2))/ 7 + 3^( n + 1)) .

\(\mathop {\lim }\limits_{n \to + \infty } \frac{{{{5.2}^{n + 2}} - {{2.3}^{n + 2}}}}{{7 + {3^{n + 1}}}}\)\( = \mathop {\lim }\limits_{n \to + \infty } \frac{{5.4.{{\left( {\frac{2}{3}} \right)}^n} - 2.9}}{{7.{{\left( {\frac{1}{3}} \right)}^n} + 3}}\)\( = \frac{{ - 18}}{3} = - 6\).

Trả lời: −6.