Answer:
{x ≠ -3 ∪ x ± 4}
Step-by-step explanation:
The (x - 4) terms cancel, but x still may not = 4 (which would cause division by zero). Also, (x + 3) may not be zero (for the same reason), and so x ≠ -3.
The domain of this function is {x ≠ -3 ∪ x ± 4}