Question

упростите выражение ​

Answer 1

$( \frac{1}{x} - \frac{1}{y} ) \times \frac{1}{x - y} = \frac{y - x}{xy} \times \frac{1}{x - y} = \\ \frac{ - (x - y)}{xy} \times \frac{1}{x - y} = \frac{ - 1}{xy} = - \frac{1}{xy}$

Answer 2

$(x^{-1}-y^{-1} )*(x-y)^{-1}=(\frac{1}{x}-\frac{1}{y})*\frac{1}{x-y} =\frac{y-x}{xy}*\frac{1}{x-y}=-\frac{1}{xy}\\\\Otvet:\boxed{-\frac{1}{xy}}$