Answer:
\frac{1}{y-x} [tex]\frac{x^{-1}+y^{-2} }{x^{-1} .y-x.y^{-1} }\\ = (\frac{1}{x} +\frac{1}{y} ):(\frac{y}{x} -\frac{x}{y})\\ = (\frac{x+y}{xy} ):(\frac{y^{2} - x^{2} }{xy}) \\= \frac{x+y}{y^{2} -x^{2} } \\=\frac{x+y}{(x+y).(y-x)} \\=\frac{1}{y-x}[/tex]
Step-by-step explanation: