The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 2.2437\\[1 em]x_2 &= -0.3718+0.7282i\\[1 em]x_3 &= -0.3718-0.7282i \end{aligned} $$Polynomial $ -2x^3+3x^2+2x+3 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.