\(\left(x^2-3\right)^2-\left(8x-6\right)\left(x^2-3\right)+\left(3-4x\right)^2=0\)
\(\Rightarrow\left(x^2-3\right)^2-2\left(4x-3\right)\left(x^2-3\right)+\left(3-4x\right)^2=0\)
\(\Rightarrow\left(x^2-3\right)^2+2\left(3-4x\right)\left(x^2-3\right)+\left(3-4x\right)^2=0\)
\(\Rightarrow\left(x^2-3+3-4x\right)^2=0\)
\(\Rightarrow\left(x^2-4x\right)^2=0\)
\(\Rightarrow x^2-4x=0\)
\(\Rightarrow x\left(x-4\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x-4=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x=4\end{matrix}\right.\)