\[\left\{ \begin{matrix}
7x + 4y = 10 \\
2x + 3y = 1\ \ \ \\
\end{matrix} \right.\ \]
\[(2; - 1):\]
\[\left\{ \begin{matrix}
7 \cdot 2 + 4 \cdot ( - 1) = 10 \\
2 \cdot 2 + 3 \cdot ( - 1) = 1\ \ \\
\end{matrix} \right.\ \]
\[\left\{ \begin{matrix}
14 - 4 = 10 \\
4 - 3 = 1\ \ \ \ \ \\
\end{matrix} \right.\ \]
\[\left\{ \begin{matrix}
10 = 10 \\
1 = 1\ \ \ \ \ \\
\end{matrix} \right.\ \]
\[Является.\]