\[\boxed{\text{326\ (326).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
Пояснение.
Решение.
\[1)\ \overline{\text{cba}} = 100c + 10b + a.\]
\[2)\ \overline{\text{abc}} - \overline{\text{ab}} =\]
\[= 100a + 10b + c - 10a - b =\]
\[= 100a + 9b - 10a + c =\]
\[= 90a + 9b + c.\]
\[3)\ \overline{a0c} + \overline{\text{ac}} =\]
\[= 100a + c + 10a + c =\]
\[= 110a + 2c.\ \ \]