For this case we have:
We locate the given points on the negative axis of the x coordinate
We shadow the region between both points
The shaded region will be the difference or distance between both numbers.
Algebraically, the difference is given by:
[tex]| -13 - (- 4) | = | -9 | = 9\\[/tex]
Answer:
[tex]Distance = 9\\[/tex]
See attached image