The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 5.841\\[1 em]x_2 &= -0.0205+0.4891i\\[1 em]x_3 &= -0.0205-0.4891i \end{aligned} $$Polynomial $ 5x^3-29x^2-7 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.