\[\left\{ \begin{matrix} 7 \cdot (2x - 3) - 3 \cdot (4y - 3) = 20 \\ 0,3x + 0,2y = 1,6\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ | \cdot 10 \\ \end{matrix} \right.\ \]
\[\left\{ \begin{matrix} 14x - 21 - 12y + 9 = 20 \\ 3x + 2y = 16\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\ \end{matrix} \right.\ \]
\[\left\{ \begin{matrix} 14x - 12y = 32\ \ \ \ \\ 3x + 2y = 16\ \ | \cdot 6 \\ \end{matrix} \right.\ \Longrightarrow \left\{ \begin{matrix} 14x - 12y = 32 \\ 18x + 12y = 96 \\ \end{matrix} \right.\ ( + )\]
\[32x = 128\]
\[x = 128\ :32\]
\[x = 4.\]
\[2y = 16 - 3x = 16 - 3 \cdot 4 = 16 - 12\]
\[2y = 4\]
\[y = 2.\]
\[\left\{ \begin{matrix} x_{0} = 4 \\ y_{0} = 2 \\ \end{matrix} \right.\ \]
\[x_{0} - y_{0} = 4 - 2 = 2.\]
\[Ответ:2)\ 2.\]