Chapter 4 - Proportions, Percents, and Solving Inequalities - Chapter 4 Review Problem Set - Page 183: 7

$x=-60$

Using cross-multiplication and the properties of equality, the value of the variable that satisfies the given equation, $ \dfrac{x-3}{9}=\dfrac{x+4}{8} ,$ is \begin{array}{l}\require{cancel} 8(x-3)=9(x+4) \\\\ 8x-24=9x+36 \\\\ 8x-9x=36+24 \\\\ -x=60 \\\\ x=-60 .\end{array}