Construct a polynomial g(x) with integer coefficents and roots 1, 2/3, and 4i

(x-1)(3x-2)(x-4i) but (x-4i)is not allowed alone, we also need its complex conjugate

(x-1)(3x-2)(x-4i)(x+4i)

I get
3x^4-5x^3+50x^2-80x+32