Ok I figured out how to find (FoG)(x) etc. but I am confused on how to find just plain FoG or GoF. For example f(x)=x^2+6 g(x)=sqrt(x-6). How do I find FoG GoF FoF and GoG of these?? Thank you sooo much for your time!!

Ok I figured out how to find (FoG)(x) etc. but I am confused on how to find just plain FoG or GoF. For example f(x)=x^2+6 g(x)=sqrt(x-6). How do I find FoG GoF FoF and GoG of these?? Thank you sooo much for your time!!

OK, start with the inside [eg if it'd FoG then start with G, if it's GoF then start with F. ] You will now have a solution for the inside. NOW when ever you see an X in the outside, substitute your solution.
Bingo !!