Question

I don't have 20 characters long question!!​

Answer 1

$\frac{x {}^{ - 1} y {}^{ - 1} }{x {}^{ - 1} + y {}^{ - 1} }$

then divide both numerator and denominator by

${x}^{ - 1} y {}^{ - 1}$

then,

$\frac{1}{ \frac{1}{ {y}^{ - 1} } + \frac{1}{ {x}^{ - 1} } }$

then,

$\frac{1}{y + x}$

yr answer I hope it help you....