ГДЗ по алгебре 8 класс Макарычев ФГОС Задание 1096

\[\boxed{\text{1096.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]

\[\textbf{а)}\ x² + 7x + 12 = 0\]

\[x_{1} + x_{2} = - 7;\ \ \ x_{1} \cdot x_{2} = 12\]

\[x_{1} = - 3;\ \ x_{2} = - 4.\]

\[Ответ:x = - 3;x = - 4.\]

\[\textbf{б)}\ x² - 2x - 35 = 0\]

\[D_{1} = 1 + 35 = 36\]

\[x_{1} = 1 + 6 = 7;\ \ \]

\[\ x_{2} = 1 - 6 = - 5.\]

\[Ответ:x = 7;x = - 5.\]

\[\textbf{в)}\ 2x² - 5x - 3 = 0\]

\[D = ( - 5)^{2} + 4 \cdot 2 \cdot 3 =\]

\[= 25 + 24 = 49\]

\[x_{1} = \frac{5 + 7}{4} = 3;\ \ \ \]

\[x_{2} = \frac{5 - 7}{4} = - \frac{2}{4} = - 0,5.\]

\[Ответ:x = 3;x = - 0,5.\]

\[\textbf{г)}\ 3x² - 8x + 5 = 0\]

\[D_{1} = 16 - 15 = 1\]

\[x_{1} = \frac{4 + 1}{3} = \frac{5}{3} = 1\frac{2}{3};\ \ \ \]

\[x_{2} = \frac{4 - 1}{3} = 1.\]

\[Ответ:x = 1;\ \ x = 1\frac{2}{3}.\]