The root of polynomial $ p(x) $ is:
$$ \begin{aligned}x &= \frac{ 3 }{ 11 } \end{aligned} $$Step 1:
Combine like terms:
$$ \color{blue}{3x} + \color{blue}{8x} -3 = \color{blue}{11x} -3 $$Step 2:
$$ \begin{aligned} 11x-3 & = 0 \\[1 em] 11 \cdot x & = 3 \\[1 em] x & = \frac{ 3 }{ 11 } \end{aligned} $$