The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 0.794\\[1 em]x_2 &= -4.1477\\[1 em]x_3 &= -0.3232+1.4217i\\[1 em]x_4 &= -0.3232-1.4217i \end{aligned} $$Polynomial $ x^4+4x^3+x^2+5x-7 $ has no rational roots that can be found using Rational Root Test, so the roots were found using quartic formulas.