\[5x + py - 3p = 0;\ \ \ \ \ \ \ \ \ (1;1)\]
\[5 \cdot 1 + p \cdot 1 - 3 \cdot p = 0\]
\[5 + p - 3p = 0\]
\[- 2p = - 5\]
\[p = 2,5\]
\[Ответ:\ \ при\ p = 2,5.\]