a: \(\Leftrightarrow\left\{{}\begin{matrix}12x+8y=32\\12x-9y=-36\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}17y=68\\3x+2y=8\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=4\\x=0\end{matrix}\right.\)
b: \(\Leftrightarrow\left\{{}\begin{matrix}x\left(\sqrt{3}+1\right)=\sqrt{3}+1\\x+y=\sqrt{3}\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=1\\y=\sqrt{3}-1\end{matrix}\right.\)