Chapter 5 - Exponents and Polynomials - 5.6 - Integral Exponents and Scientific Notation - Problem Set 5.6 - Page 224: 77

$\dfrac{x^{2}}{y^{6}}$

Using the laws of exponents, the given expression, $ \left( \dfrac{x^{-1}}{y^{-3}} \right)^{-2} ,$ is equivalent to \begin{array}{l}\require{cancel} \dfrac{x^{-1(-2)}}{y^{-3(-2)}} \\\\= \dfrac{x^{2}}{y^{6}} .\end{array}