Ta có: \(2,8:\left(\frac{1}{5}-3x\right)=\frac{7}{5}\)
\(\Leftrightarrow\frac{14}{5}:\left(\frac{1}{5}-3x\right)=\frac{7}{5}\)
\(\Leftrightarrow\frac{1}{5}-3x=2\)
\(\Leftrightarrow3x=\frac{1}{5}-2=\frac{9}{5}\)
hay \(x=\frac{3}{5}\)
Vậy: \(x=\frac{3}{5}\)