Question

giải hệ phương trình 

\(\left\{{}\begin{matrix}2x+y=3\\x+3y=4\end{matrix}\right.\)

Answer 1

\(\left\{{}\begin{matrix}2x+y=3\\x+3y=4\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}2x+y=3\\2x+6y=8\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}5y=5\\2x+y=3\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}y=1\\2x=3-y=3-1=2\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}y=1\\x=1\end{matrix}\right.\)