Question 123784
{{{(x^-2)/((x^-2)-(y^-2))}}} 

{{{(1/x^2)/((1/x^2)-(1/y^2))}}} 

 {{{LCD = x^2y^2}}} 


{{{(1/x^2)/((y^2 - x^2)/x^2y^2))}}}.........multiply outer and inner terms 

{{{x^2y^2/(y^2 - x^2)}}}.........

{{{x^2y^2/(y -x)(y+x)}}}.........