The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -0.4542\\[1 em]x_2 &= -0.7951+0.8158i\\[1 em]x_3 &= -0.7951-0.8158i\\[1 em]x_4 &= 0.6524+0.3407i\\[1 em]x_5 &= 0.6524-0.3407i\\[1 em]x_6 &= 0.5365+1.1307i\\[1 em]x_7 &= 0.5365-1.1307i \end{aligned} $$Polynomial $ 6x^7-2x^6+4x^5+2x^4+7x^3-9x^2+x+3 $ has no rational roots that can be found using Rational Root Test, so the roots were found using Newton method.