Answer
$|x-3|\le4$
Work Step by Step
Halfway between the boundaries of the given graph, $-1$ and $7,$ is $3.$ From $3,$ the points on the graph represent all numbers that are less than or equal to $4$ units away. Hence, the given graph is equivalent to:
\begin{array}{l}\require{cancel}
|x-3|\le4
.\end{array}