LN=8 because every time there is a midpoint you have to divide it in half. So 64,32,16,8
Use the slope formula
y2-y1
m=---------
x2-x1
(rise-->y over run-->x)
so it would be
9-5
m=-------
1-10
and that would simplify to
4
----
-9
and that would be your slope.
Hope that helped :-)