F(x)=4x^4−20x^3+9x^2−54x+45 and g(x)=x−5, find (f/g)(x) and (f/g)(−4)

If you double the input of a function and it results in half the output, and if you triple the input and it results in a third of the output, what can be guessed about the function? check all that apply.