Toán Lớp 8: -2x – 2/3(3/4 – 1/8x)= (-1/2)^3, giúp em giải bài này ạ, em cảm ơn thầy cô và các bạn nhiều.
\[\begin{array}{l}– 2x – \frac{2}{3}(\frac{3}{4} – \frac{1}{8}x) = {(\frac{{ – 1}}{2})^3}\\= > – 2x – \frac{1}{2} + \frac{1}{{12}}x = \frac{{ – 1}}{8}\\= > – \frac{{23}}{{12}}x = \frac{{ – 1}}{8} + \frac{1}{2}\\= > \frac{{ – 23}}{{12}}x = \frac{3}{8}\\= > x = \frac{3}{8}:(\frac{{ – 23}}{{12}})\\= > x = \frac{{ – 9}}{{46}}\end{array}\] Trả lời
– 2x – \frac{2}{3}(\frac{3}{4} – \frac{1}{8}x) = {(\frac{{ – 1}}{2})^3}\\
= > – 2x – \frac{1}{2} + \frac{1}{{12}}x = \frac{{ – 1}}{8}\\
= > – \frac{{23}}{{12}}x = \frac{{ – 1}}{8} + \frac{1}{2}\\
= > \frac{{ – 23}}{{12}}x = \frac{3}{8}\\
= > x = \frac{3}{8}:(\frac{{ – 23}}{{12}})\\
= > x = \frac{{ – 9}}{{46}}
\end{array}\]