The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -0.623+24.0302i\\[1 em]x_2 &= -0.623-24.0302i\\[1 em]x_3 &= -11.377+61.3545i\\[1 em]x_4 &= -11.377-61.3545i \end{aligned} $$Polynomial $ x^4+24x^3+4500x^2+18000x+2250000 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.