## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

$8$
The distance between two points on the real number line with coordinates $a$ and $b$ is given by $d$ where: $$d= |b-a|$$ Here we have: $a=-3 \hspace{30pt} b=5$ Thus, $d= |5-(-3)| = |8| = \boxed{8}$