The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -1+3i\\[1 em]x_2 &= -1-3i\\[1 em]x_3 &= -3+i\\[1 em]x_4 &= -3-i \end{aligned} $$Polynomial $ x^4+8x^3+32x^2+80x+100 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.