Question

giải hệ phương trình sau
.{ 3x-y = 5
 { 5x + 2y = 23

Answer 1

\(\Leftrightarrow\left\{{}\begin{matrix}6x-2y=10\\5x+2y=23\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}11x=33\\5x+2y=23\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}x=3\\15+2y=23\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=3\\y=4\end{matrix}\right.\)

Answer 2

\(\left\{{}\begin{matrix}3x-y=5\\5x+2y=23\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}-6x+2y=-10\\5x+2y=23\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}3x-y=5\\11x=33\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}x=3\\y=4\end{matrix}\right.\)