Question 1022997
I hope you can see the process from this graph 

*[illustration Screen_shot_2016_03_11_at_11.09.44_AM.jpg]

I drew the line y=5 and show the reflected points. (-3,2) reflects up to (-3,8). See how it's 3 up to the line? The reflection is 3 higher than that, so the line is the midpoint of the point and its reflection.