Answer
$|x-5|\lt1$
Work Step by Step
The expression, $|x-a|\lt b,$ means the distance of $x$ from $a$ is less than $b$ units. Hence, the given description, "$x$ is less than 1 unit from $5$," in symbols, is equivalent to
\begin{array}{l}\require{cancel}
|x-5|\lt1
.\end{array}