ГДЗ по алгебре 8 класс Макарычев ФГОС Задание 1316

\[\boxed{\text{1316.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]

\[\textbf{а)}\ xy + 3x = 0\ \ \]

\[xy = - 3x\]

\[y = - \frac{3x}{x}\ \]

\[\ y = - 3;\ \ x \neq 0.\]

\[\textbf{б)}\ (x - y)(y - 5) = 0\]

\[x - y = 0;\ \ \ \ y - 5 = 0\]

\[y = x;\ \ \ \ \ \ \ \ \ \ \ \ y = 5.\]

\[\textbf{в)}\ (xy - 6)(y - 3) = 0\]

\[xy - 6 = 0;\ \ \ \ \ \ \ \ y - 3 = 0\]

\[xy = 6\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ y = 3\]

\[y = \frac{6}{x}\]

\[\textbf{г)}\ (x - y)^{2} + (x - 1)^{2} = 0\]

\[\left\{ \begin{matrix} (x - y)^{2} \geq 0 \\ (x - 1)^{2} \geq 0 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ }\left\{ \begin{matrix} x - y = 0 \\ x - 1 = 0 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ }\]

\[\left\{ \begin{matrix} x = y \\ x = 1 \\ \end{matrix} \right.\ ;\ \ то\ есть,\ \]

\[это\ точка\ (1;1).\]

\[\textbf{д)}\ x² - 4 = 0\]

\[x^{2} = 4\]

\[x = \pm 2\]

\[\textbf{е)}\ y² - 9 = 0\]

\[y^{2} = 9\]

\[y = \pm 3.\]