I'm supposed 2 simplify this, and according to my Barron's Precalc The EZ way, the answer is B^n.
So far, I've not gotten there, but hopefully I will soon. So far, I've not had issues with this problem set, but for some reason, this one and the next one (same type of problem) are stumping me.
I will continue working with this and hopefully will get it, soon. I suspect that I need to start with the paranthetical cube in the numerator, but I feel like I'm 15 yrs old again (I'm in my 40s ☺) staring at my text book. Good grief, and this was my idea to try this book on for size.