\(\left(\dfrac{2x}{3}-3\right):\left(-10\right)=\dfrac{2}{5}\)
\(\dfrac{2x}{3}-3=\dfrac{2}{5}\times\left(-10\right)\)
\(\dfrac{2x}{3}-3=-4\)
\(\dfrac{2x}{3}=-4+\left(-3\right)\)
\(\dfrac{2x}{3}=-7\)
\(\)\(2.x:3=-7\)
\(2x=-7\times3\)
\(2x=-21\)
\(x=-21:2\)
\(x=-\dfrac{21}{2}\)