\[(x - y)^{2} + (y - 3)^{2} = 0\]
\[\left\{ \begin{matrix} x - y = 0 \\ y - 3 = 0 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ }\]
\[\left\{ \begin{matrix} y = x \\ y = 3 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ }\]
\[\left\{ \begin{matrix} x = 3 \\ y = 3 \\ \end{matrix} \right.\ \]
\[Ответ:(3;3).\]