The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -0.2647\\[1 em]x_2 &= -5.363\\[1 em]x_3 &= 0.3139+1.4193i\\[1 em]x_4 &= 0.3139-1.4193i \end{aligned} $$Polynomial $ x^4+5x^3+11x+3 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.