1) $$\frac{3}{4}$$ от 32 =$$\frac{3}{4} \cdot 32$$=$$\frac{3 \cdot 32}{4}$$=$$\frac{3 \cdot 8}{1}$$=24
2) $$\frac{3}{8}$$ от $$\frac{4}{9}$$ =$$\frac{3}{8} \cdot \frac{4}{9}$$ =$$\frac{1}{2} \cdot \frac{1}{3}$$ =$$\frac{1}{6}$$
3) $$\frac{13}{15}$$ от 1$$\frac{5}{39}$$ =$$\frac{13}{15} \cdot \frac{44}{39}$$ =$$\frac{1}{15} \cdot \frac{44}{3}$$ =$$\frac{44}{45}$$
4) 1$$\frac{5}{16}$$ от 2$$\frac{7}{25}$$ =$$\frac{21}{16} \cdot \frac{57}{25}$$ =$$\frac{21 \cdot 57}{16 \cdot 25}$$ =$$\frac{1197}{400}$$= 2$$\frac{397}{400}$$
Ответ: 1) 24; 2) $$\frac{1}{6}$$; 3) $$\frac{44}{45}$$; 4) 2$$\frac{397}{400}$$