Ответ:
\(2-1\frac{13}{28}=2-\frac{41}{28}=\frac{15}{28}\).
\(\frac{15}{28}:\frac{25}{49}=\frac{15}{28}\cdot\frac{49}{25}=\frac{21}{20}\).
\(\frac8{15}+\frac{21}{20}-\frac54=\frac{32+63-75}{60}=\frac13\).
Ответ: \(\frac13\).
\(2-1\frac{13}{28}=2-\frac{41}{28}=\frac{15}{28}\).
\(\frac{15}{28}:\frac{25}{49}=\frac{15}{28}\cdot\frac{49}{25}=\frac{21}{20}\).
\(\frac8{15}+\frac{21}{20}-\frac54=\frac{32+63-75}{60}=\frac13\).
Ответ: \(\frac13\).