Answer:
[tex]4\sqrt{5}[/tex] units
Step-by-step explanation:
The distance between any two points on the x y plane (a,b) and (c,d) has one of two formulas. [tex]\sqrt{(a-c)^2+(b-d)^2}[/tex] or [tex]\sqrt{(c-a)^2+(d-b)^2}[/tex] if you use c-a you have to also use d-b, and the other way around for a-c and b-d. You can rearrange which order you add though. So with (-1,5) and (3,3) here is the math
[tex]\sqrt{(3-(-1))^2+((-3)-5)^2} \\\sqrt{4^2+(-8)^2} \\\sqrt{16+64}\\\sqrt{80}[/tex]
You could simplify this to [tex]4\sqrt{5}[/tex]
Let me know if there was anything you didn't understand.