The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -5.6462\\[1 em]x_2 &= 2.8231+4.8898i\\[1 em]x_3 &= 2.8231-4.8898i \end{aligned} $$Polynomial $ x^3+180 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.