Представьте в виде дроби: ((x+y)/(x-y)-(x-y)/(x+y)):xy/(x^2-y^2).

\[\left( \frac{x + y}{x - y} - \frac{x - y}{x + y} \right)\ :\frac{\text{xy}}{x^{2} - y^{2}} = 4\ \]

\[1.\ \ \frac{x + y^{\backslash x + y}}{x - y} - \frac{x - y^{\backslash x - y}}{x + y} =\]

\[= \frac{(x + y)^{2} - (x - y)^{2}}{(x - y)(x + y)} =\]

\[= \frac{x^{2} + 2xy + y^{2} - x^{2} + 2xy - y^{2}}{x^{2} - y^{2}} =\]

\[= \frac{4xy}{x^{2} - y^{2}}\]

\[2.\ \ \frac{4xy \cdot (x^{2} - y^{2})}{\left( x^{2} - y^{2} \right) \cdot xy} = 4\]