I'm stuck! Well, I guess that goes without saying or I wouldn't be posting.
Although I'm studying pre-calculus right now (implicit domains of composite functions), I am having trouble with an ugly fraction (well, I think so).
I can figure out the composite function with no problem, but they have simplified it to something else and I don't know how they got from this:
to this:
I am sticking with the bottom first, and trying to find a common denominator to subtract
I tried using
So how did they get from