Question 929567
You should have {{{(3x)/(1-2x)}}} for your (f o g)(x) when everything is completely simplified. 


You'll find that x cannot be zero (due to the division by zero error in g(x)) and that x cannot be 1/2 (due to the division by zero error in (f o g)(x)). 


It turns out that x = 6 works just fine in both g(x) and (f o g)(x), so x = 6 is allowed in the domain of the composite function.


The value x = 6 doesn't work in f(x), but that doesn't matter as the x-6 turns into 1-2x when we get to (f o g)(x).