Ok so I kind of forgot how to do this so I looked up on the internet and was told divide the coefficent in the numerator of the highest degree by the highest coeficent of the highest degree in the numerator and that should be your horizontal asymptote
one problem
f(x) = (x^2 -4)/(x^2 - x - 12)
the coefficents are one in the numerator and one in the denomenator so the horizontal asymptote should be 1 but its not as f(-8) is exactly one so... what's up with that?