Question

How do you find the domain of `f(x) = {(x - 1)/(x + 4)}`?

Answer 1

The domain represents the set of `x` values that your function can accept.
In your case the only value that cannot be accepted is the one that makes the denominator equal to zero, i.e., `x=-4` (you cannot divide by zero).
So your domain is all real `x` except `x=-4`.