Answer:
All real numbers except for x = -2/3 (which makes gof undefined)
Explanation:
g(x) = 1/ (x+2)
Domain = All real numbers except for x = -2 (which makes g(x) undefined)
h(x) = 3x
Domain = All real numbers
g(h(x)) = gof
g(h(x)) = gof = 1/ (3x+2)
Where
(3x+2) ≠ 0
x ≠ -2/3
The new domain of gof is
All real numbers except for x = -2/3 (which makes gof undefined)