Đáp án:
\(\left\{ \begin{array}{l}
x = 4\\
y = - 1
\end{array} \right.\)
Giải thích các bước giải:
\(\begin{array}{l}
\left\{ \begin{array}{l}
2x + 3y = 5\\
3x + 5y = 7
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
6x + 9y = 15\\
6x + 10y = 14
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
y = - 1\\
6x + 10.\left( { - 1} \right) = 14
\end{array} \right.\\
\Leftrightarrow \left\{ \begin{array}{l}
y = - 1\\
x = \frac{{14 + 10}}{6} = 4
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
x = 4\\
y = - 1
\end{array} \right.
\end{array}\)
