Plz help me with this problem

Can somebody 1. what is the formula for finding the vertical distance between two points on a coordinate plane?

Find the nonpermissible replacement for binthis expression. b2/5b +5

Atriangle has verticals at b(-3,0), c(2,-1), d(-1,2). which transformation would produce an image with verticals b”(-2,1), c”(3,2), d”(0,-1)?