Đáp án:
Giải thích các bước giải:
\(\begin{array}{l}
\mathop {\lim }\limits_{x \to {1^ + }} \left( {\frac{1}{{x - 1}} - \frac{3}{{{x^3} - 1}}} \right) = \mathop {\lim }\limits_{x \to {1^ + }} \frac{{{x^2} + x + 1 - 3}}{{\left( {x - 1} \right)\left( {{x^2} + x + 1} \right)}}\\
= \mathop {\lim }\limits_{x \to {1^ + }} \frac{{\left( {x - 1} \right)\left( {x + 2} \right)}}{{\left( {x - 1} \right)\left( {{x^2} + x + 1} \right)}}\\
= \mathop {\lim }\limits_{x \to {1^ + }} \frac{{x + 2}}{{{x^2} + x + 1}} = \frac{{1 + 2}}{{1 + 1 + 1}} = 1
\end{array}\)
