Bài 2:
\(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{1}{4}x-8=0\\y^2-\dfrac{1}{9}=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=32\\y\in\left\{\dfrac{1}{3};-\dfrac{1}{3}\right\}\end{matrix}\right.\)
Bài 3:
\(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{1}{2}x-3=0\\y^2-\dfrac{1}{4}=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=6\\y\in\left\{\dfrac{1}{2};-\dfrac{1}{2}\right\}\end{matrix}\right.\)