Đáp án:
$\begin{array}{l}
\left\{ \begin{array}{l}
3x - 4y = - 2\\
5x + 2y = 14
\end{array} \right. \Rightarrow \left\{ \begin{array}{l}
3x - 4y = - 2\\
10x + 4y = 28
\end{array} \right.\\
\Rightarrow \left\{ \begin{array}{l}
\left( {3x - 4y} \right) + \left( {10x + 4y} \right) = - 2 + 28\\
5x + 2y = 14
\end{array} \right.\\
\Rightarrow \left\{ \begin{array}{l}
13x = 26\\
2y = 14 - 5x
\end{array} \right.\\
\Rightarrow \left\{ \begin{array}{l}
x = 2\\
y = \frac{{14 - 5x}}{2} = \frac{{14 - 5.2}}{2} = 2
\end{array} \right.\\
Vậy\,\left( {x;y} \right) = \left( {2;2} \right)
\end{array}$
