7) \(\frac{y}{x(x+y)}-\frac{x}{y(x+y)}\)

\(\frac{y^2-x^2}{xy(x+y)}=\frac{(y-x)(y+x)}{xy(x+y)}=\frac{y-x}{xy}\).

Ответ: \(\frac{y-x}{xy}\).