Answer
$\text{Set Builder Notation: }
\{x|x\le-7\}
\\\text{Interval Notation: }
(-\infty,-7]$
Work Step by Step
The given inequality, $
x\le-7
,$ can be written in the following formats:
\begin{array}{l}\require{cancel}
\text{Set Builder Notation: }
\{x|x\le-7\}
\\\text{Interval Notation: }
(-\infty,-7]
.\end{array}
Note that in the interval notation, use parentheses for $\lt$ or $\gt.$ Use a bracket for $\le$ or for $\ge.$
In the graph, a hollowed dot is used for $\lt$ or $\gt.$ A solid dot is used for $\le$ or $\ge.$