\[\boxed{\text{545.}\text{\ }\text{ОК\ ГДЗ\ -\ домашка\ на\ 5}}\]
\[\textbf{а)}\ \frac{1}{3};\ - 1;\ldots\]
\[a_{1} = \frac{1}{3};\ \ a_{2} = - 1;\ \ \]
\[d = a_{2} - a_{1} = - 1 - \frac{1}{3} = - \frac{4}{3}\]
\[a_{n} = \frac{1}{3} - \frac{4}{3} \cdot (n - 1)\]
\[a_{10} = \frac{1}{3} - \frac{4}{3} \cdot 9 = \frac{1}{3} - 12 =\]
\[= - 11\frac{2}{3}.\]
\[\textbf{б)}\ 2,3;\ \ 1;\ldots\ \]
\[a_{1} = 2,3;\ \ \ \ a_{2} = 1;\ \ \]
\[d = a_{2} - a_{1} = 1 - 2,3 = - 1,3;\]
\[a_{n} = 2,3 - 1,3 \cdot (n - 1);\]
\[a_{10} = 2,3 - 1,3 \cdot (10 - 1) =\]
\[= - 9,4.\]