posted by mary .
Find the distance between each pair of points.
This one is easy, notice that both your points are on the x-axis.
So you are just going from -3 to +4 which would be 7 units
in general for two points (x1,y1) and (x2,y2)
the distance between them is
SQRT((x2-x1)^2 + (y2-y1)^2)