Construct the perpendicular bisector of ST
The answer is:
6 = 9x + 27
depending on what you are supposed to do.
The domain is all of the possible x values, and there are none less than -3 in this case, so the answer is B, which shows that x must be greater than or equal to -3.
I believe they would all be 20/1 because 60/3 is 20/1 and 80/4 is 20/1 as well