\[\boxed{\text{217.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
Пояснение.
Решение.
\[\textbf{а)}\ \frac{\overline{a0a0}}{101} = \frac{1000a + 10a}{101} =\]
\[= \frac{1010a}{101} = 10a\]
\[\textbf{б)}\ \frac{\overline{a00a}}{91} = \frac{1000a + a}{91} =\]
\[= \frac{1001a}{91} = 11a\]