Question

              1              =??????/
       (x-² + y-²)-¹

Answer 1

                1          inverso da divisão
       (x-² + y-²)-¹

 x^-2 + y^-2
  1  +  1
  x^2   y^2

    x^2 + y^2  
     x^2y^2

Answer 2

Olá, Denner.

$\frac1{(x^{-2} + y^{-2})^{-1}}=\frac1{\frac1{(x^{-2} + y^{-2})}}=x^{-2} + y^{-2}= \\\\ =\frac1{x^2}+\frac1{y^2}=\frac{y^2+x^2}{x^2y^2}= \\\\ =\boxed{\frac{x^2+y^2}{x^2y^2}}$