Question

What is the domain of `f(x) = {(x - 1)/(x + 4)}`?

Answer 1

`f(x)=((x-1)/(x+4))`
has a domain of all values for which `f(x)` is defined.

`f(x)` is defined for all values of `x` except the value that would cause the denominator to be `=0`

That is
the domain of `f(x)`
are all values except `(-4)`

In set notation
Domain of `f(x) = (-oo,-4)uu(-4,+oo)`