$\text { Đáp án: }$
\(\left[ \begin{array}{l}2x+3y=14\\x-y=2\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}2x+3y=14\\x=2+y\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}2(2+y)+3y=14\\x=2+y\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}4+2y+3y=14\\x=2+y\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}5y=10\\x=2+y\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}y=2\\x=2+y\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}y=2\\x=2+2\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}y=2\\x=4\end{array} \right.\)
