ГДЗ по алгебре 9 класс Макарычев ФГОС Задание 550

\[\boxed{\text{551.}\text{\ }\text{ОК\ ГДЗ\ -\ домашка\ на\ 5}}\]

\[y_{n} = y_{1} + d(n - 1)\text{\ \ }\]

\[y_{n} - y_{1} = d(n - 1)\]

\[d = \frac{y_{n} - y_{1}}{n - 1}\]

\[\textbf{а)}\ y_{1} = 10;\ \ y_{5} = 22:\ \]

\[d = \frac{22 - 10}{4} = \frac{12}{4} = 3.\]

\[\textbf{б)}\ y_{1} = 28;\ \ y_{15} = - 21:\]

\[d = \frac{- 21 - 28}{14} = - 3,5.\]

\[\textbf{в)}\ y_{1} = 16;\ \ y_{8} = - 1:\ \]

\[d = \frac{- 1 - 16}{7} = - \frac{17}{7} = - 2\frac{3}{7}.\]

\[\textbf{г)}\ y_{1} = - 22;y_{16} = - 4:\]

\[d = \frac{- 4 + 22}{15} = \frac{18}{15} = \frac{6}{5} = 1,2.\]