«Деление обыкновенных дробей». 5. Реши уравнения: 1) \(\frac{4}{25}a=1\); 2) \(\frac{4}{25}b=\frac{8}{15}\); 3) \(\frac{17}{20}-\frac{4}{15}c=\frac{3}{10}\).

1. \[a=1:\frac{4}{25}=\frac{25}{4}.\]
2. \[b=\frac{8}{15}:\frac{4}{25}=\frac{8}{15}\cdot\frac{25}{4}=\frac{10}{3}=3\frac{1}{3}.\]
3. \[\frac{4}{15}c=\frac{17}{20}-\frac{3}{10}=\frac{17}{20}-\frac{6}{20}=\frac{11}{20},\] \[c=\frac{11}{20}:\frac{4}{15}=\frac{11}{20}\cdot\frac{15}{4}=\frac{33}{16}=2\frac{1}{16}.\]

Ответ: 1) \(a=\frac{25}{4}\); 2) \(b=\frac{10}{3}\); 3) \(c=\frac{33}{16}\).