Chapter 5 - Exponents and Polynomials - 5.6 - Integral Exponents and Scientific Notation - Problem Set 5.6 - Page 224: 69

$\dfrac{x^2}{25}$

Using the laws of exponents, the given expression, $ (5x^{-1})^{-2} ,$ is equivalent to \begin{array}{l}\require{cancel} 5^{-2}x^{-1(-2)} \\\\= 5^{-2}x^{2} \\\\= \dfrac{x^2}{5^2} \\\\= \dfrac{x^2}{25} .\end{array}