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

$a\lt-5 \text{ or } a\gt5$
$\bf{\text{Solution Outline:}}$ To solve the given inequality, $|a|\gt5 ,$ use the definition of a greater than (greater than or equal to) absolute value inequality. Then graph the solution set. In the graph, a hollowed dot is used for $\lt$ or $\gt.$ A solid dot is used for $\le$ or $\ge.$ $\bf{\text{Solution Details:}}$ Since for any $c\gt0$, $|x|\gt c$ implies $x\gt c \text{ or } x\lt-c$ (which is equivalent to $|x|\ge c$ implies $x\ge c \text{ or } x\le-c$), the inequality above is equivalent to \begin{array}{l}\require{cancel} a\gt5 \\\\\text{OR}\\\\ a\lt-5 .\end{array} Hence, the solution set is $a\lt-5 \text{ or } a\gt5 .$