Answer:
5
Step-by-step explanation:
You will need the distance formula.
[tex]d = \sqrt{(x_2 - x_1)^2 + (y_2-y_1)^2}[/tex]
Now you can plug in your 2 points.
A([tex]x_{1}[/tex], [tex]y_{1}[/tex])
B([tex]x_{2}[/tex], [tex]y_{2}[/tex])
[tex]d = \sqrt{(-1 - (-4))^2 + (4-8)^2}[/tex]= 5