ГДЗ по алгебре 8 класс Макарычев ФГОС Задание 752

\[\boxed{\text{752.}\text{\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]

\[ax^{2} - 3x - 5 = 0,\ \ x_{1} = 1\]

\[ax^{2} - 3x - 5 = 0\ \ \ \ |\ :a\]

\[x^{2} - \frac{3}{a}x - \frac{5}{a} = 0\]

\[по\ теореме\ Виета:\]

\[\left\{ \begin{matrix} x_{1} + x_{2} = \frac{3}{a} \\ x_{1}x_{2} = - \frac{5}{a} \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ \ \ \ }\]

\[\left\{ \begin{matrix} 1 + x_{2} = \frac{3}{a}\ \ \ \ | \cdot a \\ 1 \cdot x_{2} = - \frac{5}{a}\ \ \ \ | \cdot a \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ }\]

\[\left\{ \begin{matrix} a + ax_{2} = 3 \\ ax_{2} = - 5\ \ \ \\ \end{matrix} \right.\ \]

\[a + ( - 5) = 3\]

\[a = 8\]

\[Ответ:при\ a = 8.\ \]