I can't get how to type out the inequality sign, so I'm gonna use the equal to sign (=) even though it's wrong. If you get what I mean. I'll write the full answer in english tho.
x-4=12
collecting like terms, we have;
X=12+4
X=16( X is greater or equal to 16)
So for the graph, it'll be on 16 facing the the positive side( that's to the right) with the the end shaded.
Hope it helps