Đáp án:
\(y' = \frac{{ - 14{x^3} - 14{x^2} + 24}}{{{x^5}}}\)
Giải thích các bước giải:
\(\begin{array}{l}
y = \frac{2}{x} + \frac{1}{{{x^2}}} - \frac{6}{{7{x^4}}}\\
= \frac{{2.7{x^3} + 7{x^2} - 6}}{{7{x^4}}}\\
= \frac{{14{x^3} + 7{x^2} - 6}}{{7{x^4}}}\\
y' = \frac{{\left( {14.3.{x^2} + 7.2.x} \right).7{x^4} - 7.4.{x^3}\left( {14{x^3} + 7{x^2} - 6} \right)}}{{7{x^8}}}\\
= \frac{{294{x^6} + 98{x^5} - 392{x^6} - 196{x^5} + 168{x^3}}}{{7{x^8}}}\\
= \frac{{ - 98{x^6} - 98{x^5} + 168{x^3}}}{{7{x^8}}}\\
= \frac{{ - 14{x^3} - 14{x^2} + 24}}{{{x^5}}}
\end{array}\)
