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

$\text{Set Builder Notation: } \left\{ x|x\lt7 \right\} \\\text{Interval Notation: } \left( -\infty,7 \right)$
$\bf{\text{Solution Outline:}}$ Use the properties of inequality to solve the given inequality, $4x\lt28 .$ Write the answer in both set-builder notation and interval notation. Finally, graph the solution set. In the graph, a hollowed dot is used for $\lt$ or $\gt.$ A solid dot is used for $\le$ or $\ge.$ $\bf{\text{Solution Details:}}$ Using the properties of inequality, the given is equivalent to \begin{array}{l}\require{cancel} 4x\lt28 \\\\ x\lt\dfrac{28}{4} \\\\ x\lt7 .\end{array} Hence, the solution set is \begin{array}{l}\require{cancel} \text{Set Builder Notation: } \left\{ x|x\lt7 \right\} \\\text{Interval Notation: } \left( -\infty,7 \right) .\end{array}