Answer:
Step-by-step explanation:
The formula of a distance between x and y:
d = |y - x|
We have x = -4 and y = 5.
Substitute:
d = |5 - (-4)| = |5 + 4| = |9| = 9
9
I NEED A BIT MORE DETAIL LOL
You should be able to set up a proportion between the sides something like (18+x)/x=(56+21)/56