Chapter 3 - Equations and Problem Solving - 3.2 - Equations and Problem Solving - Problem Set 3.2 - Page 106: 29

$x=-\dfrac{25}{4}$

Using the properties of equality, the value of the variable that satisfies the given equation, $ -16-4x=9 ,$ is \begin{array}{l}\require{cancel} -4x=9+16 \\\\ -4x=25 \\\\ x=\dfrac{25}{-4} \\\\ x=-\dfrac{25}{4} .\end{array}