Упростите выражение: (x/y-y/x)*y/(x+y)-1.

\[\left( \frac{x^{\backslash x}}{y} - \frac{y^{\backslash y}}{x} \right) \cdot \frac{y}{x + y} - 1 =\]

\[= \frac{x^{2} - y^{2}}{\text{xy}} \cdot \frac{y}{x + y} - 1 =\]

\[= \frac{(x - y)(x + y)}{x(x + y)} - 1 =\]

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