X/x-y - x/x+y / xy/x+y

[latex]frac{frac{x}{x-y}-frac{x}{x+y}}{frac{xy}{x+y}}=frac{x(x+y)-x(x-y)}{(x-y)(x+y)}*frac{x+y}{xy}=frac{x^2+xy-x^2+xy}{(x-y)(x+y)}*frac{x+y}{xy}=\ =frac{2xy}{x-y}*frac{1}{xy}=frac{2}{x-y}[/latex]