Решение:

1. а) $$\frac{7}{16}$$ и $$\frac{3}{8}$$: НОЗ = 16. $$\frac{7}{16}$$ и $$\frac{3 \cdot 2}{8 \cdot 2} = \frac{6}{16}$$
2. б) $$\frac{9}{20}$$ и $$\frac{21}{60}$$: НОЗ = 60. $$\frac{9 \cdot 3}{20 \cdot 3} = \frac{27}{60}$$ и $$\frac{21}{60}$$
3. в) $$\frac{14}{75}$$ и $$\frac{13}{30}$$: НОЗ = 150. $$\frac{14 \cdot 2}{75 \cdot 2} = \frac{28}{150}$$ и $$\frac{13 \cdot 5}{30 \cdot 5} = \frac{65}{150}$$
4. г) $$\frac{17}{20}$$ и $$\frac{7}{25}$$: НОЗ = 100. $$\frac{17 \cdot 5}{20 \cdot 5} = \frac{85}{100}$$ и $$\frac{7 \cdot 4}{25 \cdot 4} = \frac{28}{100}$$
5. д) $$\frac{12}{55}$$ и $$\frac{17}{22}$$: НОЗ = 110. $$\frac{12 \cdot 2}{55 \cdot 2} = \frac{24}{110}$$ и $$\frac{17 \cdot 5}{22 \cdot 5} = \frac{85}{110}$$
6. е) $$\frac{25}{42}$$ и $$\frac{55}{147}$$: НОЗ = 294. $$\frac{25 \cdot 7}{42 \cdot 7} = \frac{175}{294}$$ и $$\frac{55 \cdot 2}{147 \cdot 2} = \frac{110}{294}$$
7. ж) $$\frac{13}{750}$$ и $$\frac{7}{450}$$: НОЗ = 2250. $$\frac{13 \cdot 3}{750 \cdot 3} = \frac{39}{2250}$$ и $$\frac{7 \cdot 5}{450 \cdot 5} = \frac{35}{2250}$$
8. з) $$\frac{21}{225}$$ и $$\frac{14}{375}$$: НОЗ = 1125. $$\frac{21 \cdot 5}{225 \cdot 5} = \frac{105}{1125}$$ и $$\frac{14 \cdot 3}{375 \cdot 3} = \frac{42}{1125}$$

Ответ: а) $$\frac{7}{16}$$ и $$\frac{6}{16}$$; б) $$\frac{27}{60}$$ и $$\frac{21}{60}$$; в) $$\frac{28}{150}$$ и $$\frac{65}{150}$$; г) $$\frac{85}{100}$$ и $$\frac{28}{100}$$; д) $$\frac{24}{110}$$ и $$\frac{85}{110}$$; e) $$\frac{175}{294}$$ и $$\frac{110}{294}$$; ж) $$\frac{39}{2250}$$ и $$\frac{35}{2250}$$; з) $$\frac{105}{1125}$$ и $$\frac{42}{1125}$$