Question

Answer 1

\(\left\{{}\begin{matrix}4x-2y=-6\\-2x+y=3\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}-2\left(2x+y\right)=-6\\-2x+y=3\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}-2x+y=3\\-2x+y=3\left(luôn.đúng\right)\end{matrix}\right.\)

Answer 2

\(\Leftrightarrow\left\{{}\begin{matrix}2x-y=-3\\-2x+y=3\end{matrix}\right.\Leftrightarrow\left(x,y\right)\in R\)