\[Центр\ окружность\ в\ точке\]
\[(3;\ - 1).\]
\[(x - 3)^{2} + (y + 1)^{2} = R^{2}\]
\[Проходит\ через\ точку\ (9; - 7)\text{.\ }\]
\[x = 9;\ \ y = - 7:\]
\[6^{2} + 6^{2} = R^{2}\]
\[R^{2} = 72\]
\[R = \sqrt{72} = 6\sqrt{2}.\]
\[Уравнение:\]
\[(x - 3)^{2} + (y + 1)^{2} = 72.\]