The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -0.0511\\[1 em]x_2 &= -0.917\\[1 em]x_3 &= 0.5936+0.3277i\\[1 em]x_4 &= 0.5936-0.3277i\\[1 em]x_5 &= 0.0334+1.0504i\\[1 em]x_6 &= 0.0334-1.0504i \end{aligned} $$Polynomial $ 42x^6-12x^5+20x^4+8x^3-30x^2+18x+1 $ has no rational roots that can be found using Rational Root Test, so the roots were found using Newton method.