\[\boxed{\text{551\ (551).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ (x - 3)^{2} + (y + 3)^{2} \leq 4\]
\[\textbf{б)}\ y \leq x^{2} - 5x + 6\ \]
\[\boxed{\text{551.}\text{\ }\text{ОК\ ГДЗ\ -\ домашка\ на\ 5}}\]
\[y_{n} = y_{1} + d(n - 1)\text{\ \ }\]
\[y_{n} - y_{1} = d(n - 1)\]
\[d = \frac{y_{n} - y_{1}}{n - 1}\]
\[\textbf{а)}\ y_{1} = 10;\ \ y_{5} = 22:\ \]
\[d = \frac{22 - 10}{4} = \frac{12}{4} = 3.\]
\[\textbf{б)}\ y_{1} = 28;\ \ y_{15} = - 21:\]
\[d = \frac{- 21 - 28}{14} = - 3,5.\]
\[\textbf{в)}\ y_{1} = 16;\ \ y_{8} = - 1:\ \]
\[d = \frac{- 1 - 16}{7} = - \frac{17}{7} = - 2\frac{3}{7}.\]
\[\textbf{г)}\ y_{1} = - 22;y_{16} = - 4:\]
\[d = \frac{- 4 + 22}{15} = \frac{18}{15} = \frac{6}{5} = 1,2.\]