The midpoint formula is x1 + x2/2,which gives us the "x" coordinate of the midpoint.  (This means, x1 + x2 divided by 2).

and..........

y1 + y2/2, which gives us the "y" coordinate of the midpoint.  (This means y1 + y2 divided by 2).

Soooooo, let's look at your points.  


x1 =  5
x2 = -3 

5 - 3/2 = 2/2 = 1   

So our "x" coordinate is 1.
(We subtracted 5 - 3 because our second "x" was a NEGATIVE 3).


Now for our "y" coordinate:

y1  = 2
y2  = 8

8 + 2/2  = 10/2 = 5   

So our "y" coordinate is 5.


The midpoint is:   (1, 5)


Hope this helps. :-)