The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= -2+2i\\[1 em]x_2 &= -2-2i \end{aligned} $$Step 1:
Combine like terms:
$$ x^2+ \color{blue}{5x} + \color{red}{6} \color{blue}{-x} + \color{red}{2} = x^2+ \color{blue}{4x} + \color{red}{8} $$Step 2:
The solutions of $ x^2+4x+8 = 0 $ are: $ x = -2+2i ~ \text{and} ~ x = -2-2i$.
You can use step-by-step quadratic equation solver to see a detailed explanation on how to solve this quadratic equation.