Did you do long division first? Since this is of the form P(x)/Q(x) and P(x) is higher order than Q(x), the form is improper. You must perform long division first. Doing that you get (x+1) with remainder (2x+5)/(x2-x-6). Add those together gives
(x3-5x-11)/(x2-x-6) = (x+1) + (2x+5)/(x2-x-6)
Now you can factor the denominator in the second term and perform a partial fraction decomposition. I have (x-3) as my A-term and (x+2) as my B-term. Then I get A = 11/5 and B = -1/5. Here is my expansion.
(x3-5x-11)/(x2-x-6) = (x+1) + (11/5)(1/(x-3)) - (1/5)(1/(x+2))
I hope this helps you out.