\(\dfrac{2x}{x^2-2xy}+\dfrac{y}{xy-2y^2}+\dfrac{4}{x^2-4y^2}\)
\(=\dfrac{2x}{x\left(x-2y\right)}+\dfrac{y}{y\left(x-2y\right)}+\dfrac{4}{\left(x-2y\right)\left(x+2y\right)}\)
\(=\dfrac{2}{x-2y}+\dfrac{1}{x-2y}+\dfrac{4}{\left(x-2y\right)\left(x+2y\right)}\)
\(=\dfrac{3}{x-2y}+\dfrac{4}{\left(x-2y\right)\left(x+2y\right)}=\dfrac{3x+6y+4}{\left(x-2y\right)\left(x+2y\right)}\)