Lim { - 9{n^2} - 1 / 3{n^2} + 2n bằng

Chọn C

\[\mathop {\lim }\limits_{n \to + \infty } \frac{{ - 9{n^2} - 1}}{{3{n^2} + 2n}} = \mathop {\lim }\limits_{n \to + \infty } \frac{{ - 9 - \frac{1}{{{n^2}}}}}{{3 + \frac{2}{n}}} = \frac{{ - 9}}{3}\]