## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$\displaystyle \{x\in \mathbb{R}|\quad -\frac{11}{3} \leq x\leq-1\}$
The inequality $|x|\leq a$ means that $\quad -a\leq x\leq a$ $|3x+7|\leq 4$ $-4\leq 3x+7\leq 4\qquad$ ... subtract 7 $-11\leq 3x\leq-3\qquad$ ... divide with $3$ (positive, inequality signs remain) $-\displaystyle \frac{11}{3} \leq x\leq-1$ Solution set = $\displaystyle \{x\in \mathbb{R}|\quad -\frac{11}{3} \leq x\leq-1\}$