The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 9.6733\\[1 em]x_2 &= -5.8366+9.2656i\\[1 em]x_3 &= -5.8366-9.2656i \end{aligned} $$Polynomial $ x^3+2x^2+7x-1160 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.