Решебник по алгебре 9 класс Мерзляк Задание 798

\[\boxed{\mathbf{798\ (798).\ }Еуроки\ - \ ДЗ\ без\ мороки}\]

\[a_{1} = 24;\ \ d = - 8\]

\[a_{8} = a_{1} + 7d = 24 - 7 \cdot 8 =\]

\[= 24 - 56 = - 32\]

\[a_{26} = a_{1} + 25d = 24 - 25 \cdot 8 =\]

\[= 24 - 200 = - 176\]

\[n = 26 - 8 + 1 = 19\]

\[S_{19} = \frac{a_{8} + a_{26}}{2} \cdot 19 =\]

\[= \frac{- 32 - 176}{2} \cdot 19 =\]

\[= - 104 \cdot 19 = - 1976\]

\[Ответ:\ - 1976.\]

\[\boxed{\mathbf{798.\ }Еуроки\ - \ ДЗ\ без\ мороки}\]

\[y = x^{2} - 6x + c\]

\[1)\ (0;0):\ \ \]

\[0 = 0 + c \Longrightarrow \ \ c = 0;\]

\[2)\ x_{0} = \frac{6}{2} = 3;\ \ (3;0):\ \ \]

\[0 = 9 - 18 + c \Longrightarrow \ c = 9;\]

\[3)\ A(0;\ - 4):\ \]

\[\ - 4 = 0 + c \Longrightarrow \ \ c = - 4;\]

\[4)\ \text{B\ }(2;0):\ \ \]

\[0 = 4 - 12 + c \Longrightarrow \ \ c = 8.\]