Question

Sử dụng pp cộng đại số {2x+3y=5 {3x-2y=14

Answer 1

\(\left\{{}\begin{matrix}2x+3y=5\\3x-2y=14\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}4x+6y=10\\9x-6y=42\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}4x+6y+9x-6y=10+42\\2x+3y=5\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}13x=52\\3y=5-2x\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=4\\3y=5-2\cdot4=5-8=-3\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}x=4\\y=-1\end{matrix}\right.\)