\[\boxed{\text{1029.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
\[\textbf{а)}\ a + 2b\ \ при\ \ 0 < a < 1,\]
\[\ \ - 3 < b < - 2\]
\[+ \ \left| \begin{matrix} - 6 < 2b < - 4 \\ 0 < a < 1\ \ \\ \end{matrix} \right.\ \]
\[\ \overline{- 6 < a + 2b < - 3}\]
\[\textbf{б)}\ \frac{1}{2}a - b\ \ \ при\ \ 7 < a < 10,\ \]
\[\ 14 < b < 15\]
\[+ \left| \begin{matrix} 3,5 < \frac{1}{2}a < 5 \\ - 15 < - b < - 14 \\ \end{matrix} \right.\ \]
\[\ \overline{- 11,5 < \frac{1}{2}a - b < - 9}\]