The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 0.9417\\[1 em]x_2 &= -0.7622\\[1 em]x_3 &= -2.0897+3.5144i\\[1 em]x_4 &= -2.0897-3.5144i \end{aligned} $$Polynomial $ 4x^4+16x^3+61x^2-24x-48 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.