The root of polynomial $ p(x) $ is:
$$ \begin{aligned}x &= \frac{ 37 }{ 4 } \end{aligned} $$Step 1:
Combine like terms:
$$ \color{blue}{6x} \color{blue}{-2x} \color{red}{-25} \color{red}{-12} = \color{blue}{4x} \color{red}{-37} $$Step 2:
$$ \begin{aligned} 4x-37 & = 0 \\[1 em] 4 \cdot x & = 37 \\[1 em] x & = \frac{ 37 }{ 4 } \end{aligned} $$