Đáp án:
C24: B
Giải thích các bước giải:
\(\begin{array}{l}
C21:\\
\lim \dfrac{{2x + 1}}{{x + 1}} = \lim \dfrac{{2 + \dfrac{1}{x}}}{{1 + \dfrac{1}{x}}} = 2\\
\to A\\
C22:\\
S = \dfrac{{{u_1}}}{{1 - q}} = \dfrac{1}{{1 - \left( { - \dfrac{1}{2}} \right)}} = \dfrac{2}{3}\\
\to D\\
C23:\\
\lim {\left( {\dfrac{1}{3}} \right)^n} = 0\\
\to B\\
C24:\\
\lim {x^3}\left( {1 - \dfrac{3}{x} + \dfrac{{2020}}{x}} \right) = + \infty \\
Do:\mathop {\lim }\limits_{x \to + \infty } {x^3} = + \infty \\
\mathop {\lim }\limits_{x \to + \infty } \left( {1 - \dfrac{3}{x} + \dfrac{{2020}}{x}} \right) = 1\\
\to B
\end{array}\)
