\[y = x\]
\[x = - x^{2} + 5x + 5,\ \ \ \]
\[x^{2} - 4x - 5 = 0\]
\[x_{1} + x_{2} = 4\ \ \ \ \ \ \ \ \ \ x_{1} = 5\]
\[x_{1} \cdot x_{2} = - 5\ \ \ \ \ \ \ \ \ x_{2} = - 1\]
\[Ответ:(5;5),\ \ \ ( - 1;\ - 1).\]