Draw 2y+8=0
since there's only one variable, use the number line. Go to
http://www.wolframalpha.com/input/?i=2y%2B8+%3D+0
and scroll down to the bottom to see the point plotted.
http://www.wolframalpha.com/input/?i=2y%2B8+%3D+0
and scroll down to the bottom to see the point plotted.