The roots of polynomial $ p(z) $ are:
$$ \begin{aligned}z_1 &= 1+i\\[1 em]z_2 &= 1-i\\[1 em]z_3 &= -2+i\\[1 em]z_4 &= -2-i \end{aligned} $$Polynomial $ z^4+2z^3-z^2-2z+10 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.