Tìm ẩn x biết ​\(\begin{array}{l} {\left( {\frac{1}{2}x - \frac{1}{3}} \right)^4} = \frac{{16}}{{81}} \end{array}\)

* Hướng dẫn giải

 \(\begin{array}{l} {\left( {\frac{1}{2}x - \frac{1}{3}} \right)^4} = \frac{{16}}{{81}}\\ {\left( {\frac{1}{2}x - \frac{1}{3}} \right)^4} = {\left( {\frac{2}{3}} \right)^4}\text{ hoặc }{\left( {\frac{1}{2}x - \frac{1}{3}} \right)^4} = {\left( {\frac{{ - 2}}{3}} \right)^4}\\ \frac{1}{2}x - \frac{1}{3} = \frac{2}{3}\text{ hoặc }\frac{1}{2}x - \frac{1}{3} = \frac{{ - 2}}{3}\\ \frac{1}{2}x = \frac{2}{3} + \frac{1}{3} = 1\text{ hoặc } \frac{1}{2}x = \frac{{ - 2}}{3} + \frac{1}{3} = \frac{{ - 1}}{3}\\ x = 1:\frac{1}{2} = 2\text{ hoặc } x = \frac{{ - 1}}{3}:\frac{1}{2} = \frac{{ - 2}}{3} \end{array}\)