The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 2.9422\\[1 em]x_2 &= -3.4207\\[1 em]x_3 &= -0.2608+1.2235i\\[1 em]x_4 &= -0.2608-1.2235i \end{aligned} $$Polynomial $ 4x^4+4x^3-33x^2-18x-63 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.