I know that $$x^k - p, \ \ \forall k>0\in N$$
is irreducible in $\mathbb Q[x]$ (Eisenstein theorem). I need two polynomials in $\mathbb Q[x]$ (one of degree 2 and another of degree 3) such that their product is a irreducible polynomial in $\mathbb Q[x]$. Any clue?
If that is exactly what the exercise says, then the answer is that it is not possible because, by definition, the product of two nonconstant polynomials is reducible.