Respuesta :

Let:

(3,8) = (x1,y1)

(5,-1) = (x2,y2)

Using the distance formula:

[tex]\begin{gathered} d=\sqrt[]{(x2-x1)^2+(y2-y1)^2} \\ d=\sqrt[]{(5-3)^2+(-1-8)^2} \\ d=\sqrt[]{2^2+(-9)^2}=\sqrt[]{85} \end{gathered}[/tex]