# How do you simplify x^-2÷x^-2-y^-2?

$= \frac{{y}^{2} - 1}{y} ^ 2$
${x}^{-} 2 \div {x}^{-} 2 - {y}^{-} 2 = 1 - \frac{1}{y} ^ 2 = \frac{{y}^{2} - 1}{y} ^ 2$