\(\dfrac{2}{3}+\dfrac{5}{3}x=\dfrac{5}{7}\)
\(\Rightarrow\dfrac{5}{3}x=\dfrac{5}{7}-\dfrac{2}{3}\)
\(\Rightarrow\dfrac{5}{3}x=\dfrac{15}{21}-\dfrac{14}{21}\)
\(\Rightarrow\dfrac{5}{3}x=\dfrac{15-14}{21}\)
\(\Rightarrow\dfrac{5}{3}x=\dfrac{1}{21}\)
\(\Rightarrow x=\dfrac{1}{21}:\dfrac{5}{3}\)
\(\Rightarrow x=\dfrac{1}{21}.\dfrac{3}{5}\)
\(\Rightarrow x=\dfrac{3}{105}\)
\(\Rightarrow x=\dfrac{1}{35}\)
Vậy \(x=\dfrac{1}{35}\)