Answer:
x=6 and x=12 are parallel.
Explanation:
If you graph x=6 it will be a straight verticle line on the x-axis where 6 is, same with x=12 (put a vertical line on 12 for the x-axis). When you put these both on the same graph you see they are directly across from each other but will never touch. Therefore, they are parallel. If you are writing this on paper, simply draw a graph to show this.