ГДЗ по алгебре 9 класс Макарычев Задание 521

\[\boxed{\text{521\ (521).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

\[(x - a)^{2} + (y - 3)^{2} = 16\]

\[\textbf{а)}\ \text{A\ }(2;3):\ \ \]

\[(2 - a)^{2} + (3 - 3)^{2} = 16,\ \ \]

\[(2 - a)^{2} = 16,\ \ a_{1,2} = - 2;6.\ \]

\[\textbf{б)}\ \text{B\ }(7;\ - 1):\ \ \]

\[(7 - a)^{2} + ( - 1 - 3)^{2} = 16,\ \ \]

\[(7 - a)^{2} = 0,\ \ a = 7.\ \]

\[\textbf{в)}\ C\ ( - 2;7):\ \]

\[\ ( - 2 - a)^{2} + (7 - 3)^{2} = 16,\]

\[( - 2 - a)^{2} = 0,\ \ a = - 2.\]

\[\textbf{г)}\ D\ (1;5):\ \]

\[(1 - a)^{2} + (5 - 3)^{2} = 16,\ \ \]

\[(1 - a)^{2} = 12,\ \ \]

\[a_{1,2} = 1 \pm 2\sqrt{3}.\]