Question

giải hệ phương trình : 2x-y=4 và (x-y)/2 =2

Answer 1

Ta có:

\(\left\{{}\begin{matrix}2x-y=4\\\dfrac{x-y}{2}=2\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}2x-y=4\\x-y=4\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=0\\x-y=4\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=0\\y=x-4\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=0\\y=-4\end{matrix}\right.\)

Vậy, \(S=\left\{\left(0;4\right)\right\}\)