Hey i was wondering if anyone could help me?

im doing some summer revision on algebra and i got stuck on this long division algebra question :

(x ³ + 11x - 30) ÷ (x-2)

i keep getting the answer: x ² + 9x + 36

the correct answer is : x ² + 2x + 15

i would really appreciate if anyone could help me out with this, i know it seems like a very easy question for most people but maths is my worst subject