Решебник по алгебре 8 класс Мерзляк Задание 714

\[\boxed{\mathbf{714(714).\ }Еуроки\ - \ ДЗ\ без\ мороки}\]

\[1)\ x_{1} = - 7\]

\[x_{2} = - 8\]

\[x_{1} + x_{2} = - 15\]

\[x_{1} \cdot x_{2} = 56\]

\[Уравнение:\ x² + 15x + 56 = 0\ \]

\[2)\ x_{1} = 5\]

\[x_{2} = - 0,4\]

\[x_{1} + x_{2} = 4,6\]

\[x_{1} \cdot x_{2} = - 2\ \]

\[x² - 4,6x - 2 = 0\ \ \ \ | \cdot 5\]

\[Уравнение:\ 5x^{2} - 23x - 10 = 0\]

\[3)\ x_{1} = \frac{1}{2}\]

\[x_{2} = \frac{2}{3}\]

\[x_{1} + x_{2} = \frac{7}{6}\]

\[x_{1} \cdot x_{2} = \frac{2}{6}\ \]

\[x² - \frac{7}{6}x + \frac{2}{6} = 0\ \ | \cdot 6\]

\[Уравнение:\ 6x² - 7x + 2 = 0\]

\[4)\ x_{1} = 5 - \sqrt{10}\]

\[x_{2} = 5 + \sqrt{10}\]

\[x_{1} + x_{2} = 10\]

\[x_{1} \cdot x_{2} = 25 - 10 = 15\ \]

\[Урвнение:\ x² - 10x + 15 = 0\]