Выполните действия: a) $$\frac{5}{7} - \frac{3}{8}$$ б) $$\frac{6}{25} : \frac{5}{12}$$ в) $$\frac{9}{39} \cdot \frac{13}{27}$$ г) $$\frac{24}{35} : \frac{7}{8}$$ д) $$\frac{11}{4} \cdot \frac{16}{11}$$ e) $$(\frac{3}{4})^2$$

a) $$\frac{5}{7} - \frac{3}{8} = \frac{5 \cdot 8 - 3 \cdot 7}{7 \cdot 8} = \frac{40 - 21}{56} = \frac{19}{56}$$

б) $$\frac{6}{25} : \frac{5}{12} = \frac{6}{25} \cdot \frac{12}{5} = \frac{6 \cdot 12}{25 \cdot 5} = \frac{72}{125}$$

в) $$\frac{9}{39} \cdot \frac{13}{27} = \frac{9 \cdot 13}{39 \cdot 27} = \frac{1 \cdot 1}{3 \cdot 3} = \frac{1}{9}$$

г) $$\frac{24}{35} : \frac{7}{8} = \frac{24}{35} \cdot \frac{8}{7} = \frac{24 \cdot 8}{35 \cdot 7} = \frac{192}{245}$$

д) $$\frac{11}{4} \cdot \frac{16}{11} = \frac{11 \cdot 16}{4 \cdot 11} = \frac{1 \cdot 4}{1 \cdot 1} = 4$$

e) $$(\frac{3}{4})^2 = \frac{3}{4} \cdot \frac{3}{4} = \frac{3 \cdot 3}{4 \cdot 4} = \frac{9}{16}$$