Answer
$\{x\in \mathbb{R} | x\neq 2\}$
Work Step by Step
The domain of $h/g$ is the intersection of domains of g and of h,
provided that $g(x)\neq 0.$
Both g and h are defined on $\mathbb{R}$ so we find those x for which g(x)=0:
$3x-6=0$
$3x=6$
$ x=2\qquad$ ... must be excluded from the domain
Domain = $\{x\in \mathbb{R} | x\neq 2\}$
