Chapter 5 - Exponents and Polynomials - 5.6 - Integral Exponents and Scientific Notation - Problem Set 5.6 - Page 223: 16

$-\dfrac{1}{4}$

Using $a^{-x}=\dfrac{1}{a^x}$ and the laws of exponents, the given expression, $ -(2^{-2}),$ is equivalent to \begin{array}{l}\require{cancel} \dfrac{-1}{2^2} \\\\= \dfrac{-1}{4} \\\\= -\dfrac{1}{4} .\end{array}