Tìm x biết rằng: ​\(\left| { - 2x - 1} \right| = \frac{1}{3}\)

* Hướng dẫn giải

 \(\begin{array}{l} \left| { - 2x - 1} \right| = \frac{1}{3}\\ - 2x - 1 = \frac{1}{3}\,\,hay\,\, - 2x - 1 = - \frac{1}{3}\\ - 2x = \frac{1}{3} + 1\,\,hay\,\, - 2x = - \frac{1}{3} + 1\\ - 2x = \frac{4}{3}\,\,hay\,\, - 2x = \frac{2}{3}\\ x = \frac{4}{3}:\left( { - 2} \right)\,\,hay\,\,x = \frac{2}{3}:\left( { - 2} \right)\\ x = \frac{{ - 2}}{3}\,\,hay\,\,x = \frac{{ - 1}}{3} \end{array}\)