Find distance between each pair of points.

Hi Kiona, as I bet you already know, point coordinates (locations on the X and Y axes of a graph) are listed as X first, then Y.  The first set (5,3) means at that point, X=5 and Y=3.  The second set (5,-3) means that X=5 and Y=-3

Usually the X-axis is a horizontal line, and the Y-axis is vertical, crossing the X-axis perpendicular (at right angles).  The point (0,0) is where the X and Y axes meet each other (cross).  

Since both points have X=5, both points are equally distant (+5) from the Y-axis, and therefore a line through those two points is a straight line parallel (same direction as) the Y-axis, crossing the X-axis at X=+5.  Draw it yourself so you can see it - makes it much easier to understand!

One point is +3 above the X-axis, and the other point is -3 below the X-axis.  Therefore, the total distance must be 6.