\(\left(2,1x+\frac{5}{3}\right)^6=\left(-3,2x+\frac{1}{2}\right)^6\Rightarrow2,1x+\frac{5}{3}=-3,2x+\frac{1}{2}\)
\(\Rightarrow2,1x+3,2x=\frac{1}{2}-\frac{5}{3}\)
\(5,3x=\frac{-7}{6}\)
\(x=\frac{-7}{6}:\frac{53}{10}=\frac{-35}{159}\)
Vậy \(x=\frac{-35}{159}\)