You need to multiply them 3-4 and get 12 so that's part of your answer
then you make it 12:9.
<span>{(-1, 0), (4, 3), (-7, -3), (-1, -8)}
</span> this will be the answer
F(x) = 8 - 3x
f(9) = 8 - 3(9)
= 8 - 27
= -19
hope this helps!
I've posted my answer together with the image I think this problem required.