multiplicity of a root means, is there that many times.
[tex]\bf \begin{cases}
x=3\implies &x-3=0\\
x=2\implies
&\begin{cases}
x-2=0\\
x-2=0\\
x-2=0
\end{cases}
\end{cases}
\\\\\\
(x-3)(x-2)~~(x-2)(x-2)=\textit{original polynomial}
\\\\\\
(x^2-5x+6)~~(x^2-4x+4)=y
\\\\\\
x^4-4x^3+4x^2-5x^3+20x^2-20x+6x^2-24x+24=y
\\\\\\
1x^4-9x^3+30x^2-44x+24=y[/tex]