Ответ:
а)
\(9\frac{1}{4}-8\frac{2}{8}=9\frac{1}{4}-8\frac{1}{4}=1\).
\(4\frac{3}{8}-2\frac{5}{8}=3?\) Приведём к неправильным дробям: \(\frac{35}{8}-\frac{21}{8}=\frac{14}{8}=\frac{7}{4}\).
\(1\cdot1\frac{5}{7}+\frac{7}{4}:1\frac{1}{9}=\frac{12}{7}+\frac{7}{4}\cdot\frac{9}{10}=\frac{12}{7}+\frac{63}{40}=\frac{921}{280}=3\frac{81}{280}\).
б)
\(2\frac{3}{11}\cdot\frac{1}{9}=\frac{25}{11}\cdot\frac{1}{9}=\frac{25}{99}\).
\(6\frac{8}{11}:1\frac{2}{7}=\frac{74}{11}:\frac{9}{7}=\frac{74}{11}\cdot\frac{7}{9}=\frac{518}{99}\).
\(\frac{25}{99}+\frac{518}{99}-1\frac{1}{8}=\frac{543}{99}-\frac{9}{8}=\frac{181}{33}-\frac{9}{8}=\frac{1151}{264}=4\frac{95}{264}\).
Ответ: а) \(3\frac{81}{280}\); б) \(4\frac{95}{264}\).
