Question

Решите пж умоляю прошу

Answer 1

$\frac{x^{-2}-y^{-2}}{x^{-1}-y^{-1}}=\frac{\frac{1}{x^2}-\frac{1}{y^2}}{\frac{1}{x}-\frac{1}{y}}=\frac{\frac{y^2-x^2}{x^2y^2} }{\frac{y-x}{xy}}=\frac{(y^2-x^2)\cdot xy}{(y-x)x^2y^2}=\frac{(y-x)(y+x)}{(y-x)\cdot xy}=\frac{y+x}{xy}$