Each zero 'a' gives a factor 'x-a', and noting complex zeros come in
conjugate pairs:
(x-(-5+2i))(x-(-5-2i))*(x+2)(x+2)
... after combining the terms with complex roots, and multiplying (x+2)(x+2) ...
= *
... after expansion and subsquent simplification ...
=
( checked on WolframAlpha: ' factor x^4+14x^3+73x^2+156x+116 ' yields )
