Найдите произведение или частное: а) 9/10 * 5/12 б) 3/5 : 11/15 в) 9/22 * 2/3 г) 7/8 : 7/16 д) 27/40 : 18/35 е) 8/9 : 6 ж) 15 * 5/6 з) 1 : 3/7 и) 2/3 * 12 к) 2/3 : 18 л) 8/27 * 36 м) 10 : 4/15

а) $\frac{9}{10} \times \frac{5}{12} = \frac{9 \times 5}{10 \times 12} = \frac{45}{120} = \frac{3}{8}$

б) $\frac{3}{5} : \frac{11}{15} = \frac{3}{5} \times \frac{15}{11} = \frac{3 \times 15}{5 \times 11} = \frac{45}{55} = \frac{9}{11}$

в) $\frac{9}{22} \times \frac{2}{3} = \frac{9 \times 2}{22 \times 3} = \frac{18}{66} = \frac{3}{11}$

г) $\frac{7}{8} : \frac{7}{16} = \frac{7}{8} \times \frac{16}{7} = \frac{7 \times 16}{8 \times 7} = \frac{112}{56} = 2$

д) $\frac{27}{40} : \frac{18}{35} = \frac{27}{40} \times \frac{35}{18} = \frac{27 \times 35}{40 \times 18} = \frac{945}{720} = \frac{27}{24} = \frac{9}{8}$

е) $\frac{8}{9} : 6 = \frac{8}{9} \times \frac{1}{6} = \frac{8 \times 1}{9 \times 6} = \frac{8}{54} = \frac{4}{27}$

ж) $15 \times \frac{5}{6} = \frac{15 \times 5}{6} = \frac{75}{6} = 12 \frac{1}{2}$

з) $1 : \frac{3}{7} = 1 \times \frac{7}{3} = \frac{7}{3}$

и) $\frac{2}{3} \times 12 = \frac{2 \times 12}{3} = \frac{24}{3} = 8$

к) $\frac{2}{3} : 18 = \frac{2}{3} \times \frac{1}{18} = \frac{2 \times 1}{3 \times 18} = \frac{2}{54} = \frac{1}{27}$