The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 1.5601\\[1 em]x_2 &= -1.7801+3.274i\\[1 em]x_3 &= -1.7801-3.274i \end{aligned} $$Polynomial $ 3x^3+6x^2+25x-65 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.