\(\left(\frac{4}{7}-\frac{2}{3}x\right)^3=64\)
\(\left(\frac{4}{7}-\frac{2}{3}x\right)^3=4^3\)
\(\frac{4}{7}-\frac{2}{3}x=4\)
\(-\frac{2}{3}x=4-\frac{4}{7}\)
\(-\frac{2}{3}x=\frac{24}{7}\)
\(x=\frac{24}{7}:\left(-\frac{2}{3}\right)\)
\(x=\frac{-36}{7}\)
Vậy \(x=\frac{-36}{7}\)