Explain ? ? i just need it explained how to do it step by step so i can do the next one ((:
you in advance!

L (4, 6) M (-2, 1)
The width of the line is the difference in "X" values (4 minus -2 = 6) and the height is the difference in "Y" values (6 minus 1 =5)

So the midpoint of LM will be a point that is half-way of the "X" and "Y" distances (6/2 = 3 and 5/2 - 2.5)
"X" goes from -2 to 4.  Adding 3 to -2 equals 1
"Y" goes from 1 to 6.  Adding 2.5 to 1 equals 3.5
So the midpoint = (1, 3.5)