f(x)= x^2-16 and g(x)= x+. find f/g and it’s domain

Answer 1

f/g = f(x)/g(x) = (x^2-16)/(x+?)
I expect you meant g(x) = x+4, since that would make
f/g = (x^2-16)/(x+4) = x-4
That is true for all real numbers except x = -4, as that would make f/g = 0/0, which is undefined.