G(S) =(s2+3)/(s5+s4+s3+3s2+2s) is:

s^5+s^4+s^3+3s^2+2s = s(s+1)^2(s^2-s+2)

I don't see any common factors with (s^2+3)

so, what do you mean when you ask

G(s) is: ?