Biết \(\mathop {\lim \to + \infty } f\left( x \right) = {\lim \to + \infty } g\left( x \right) = n.\) Tính \(\mathop {\lim \to + \infty } \left[ {f(x) + g(x)}

* Hướng dẫn giải

\(\begin{array}{l}\mathop {\lim }\limits_{x \to  + \infty } \left[ {f\left( x \right) + g\left( x \right)} \right]\\ = \mathop {\lim }\limits_{x \to  + \infty } f\left( x \right) + \mathop {\lim }\limits_{x \to  + \infty } g\left( x \right)\\ = m + n\end{array}\).