The root of polynomial $ p(x) $ is:
$$ \begin{aligned}x &= 0 \end{aligned} $$Step 1:
Combine like terms:
$$ \color{blue}{2x^2} \color{blue}{-3x^2} = \color{blue}{-x^2} $$Step 2:
$$ \begin{aligned} -x^2 & = 0 \\[1 em] x & = 0 \end{aligned} $$Multiplicity of this zero is equal to 2.