The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 0.3075\\[1 em]x_2 &= 1.4441\\[1 em]x_3 &= -2.2517 \end{aligned} $$Polynomial $ 2x^3+x^2-7x+2 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.