partial fraction; use the rational roots theorem to factor denominator.

x^3 + 2
-----------
x^4 +8x^2 +16

i got to that and im stuck

Ax+B + Cx+D
---- -----
x^2 +4 x^2 + 4

since x^4+8x^2+16 = (x^2+4)^2

you want

(Ax+B)/(x^2+4) + (Cx+D)/(x^2+4)^2

You must have a term for each power of repeated factors