\[x^{2} - 7x + p = 0;\ \ \ \]
\[3x_{1} - 5x_{2} = 5\]
\[\left\{ \begin{matrix} x_{1} + x_{2} = 7 \\ x_{1} \cdot x_{2} = p\ \ \\ \end{matrix} \right.\ \]
\[x_{1} = 7 - x_{2}\ \]
\[3 \cdot \left( 7 - x_{2} \right) - 5x_{2} = 5\]
\[21 - 3x_{2} - 5x_{2} = 5\]
\[- 8x_{2} = - 16 \Longrightarrow \ \ x_{2} = 2.\]
\[x_{1} = 7 - 2 \Longrightarrow \ \ x_{1} = 5.\]
\[5 \cdot 2 = p \Longrightarrow p = 10.\]
\[Ответ:\ x_{1} = 5;\ x_{2} = 2;\ p = 10.\]