(3цел 1/4 + 1цел 1/6 : 1цел 5/9) : 2цел 2/7 + 5цел 1/9 :7цел 2/3

$(3\frac{1}{4}+1\frac{1}{6}/1\frac{5}{9})/2\frac{2}{7}+5\frac{1}{9}/7\frac{2}{3} = (\frac{13}{4}+\frac{7}{6}/\frac{14}{9})/\frac{16}{7}+\frac{46}{9}/\frac{23}{3} = (\frac{13}{4}+\frac{7}{6}*\frac{9}{14})*\frac{7}{16}+\frac{46}{9}*\frac{3}{23} = (\frac{13}{4}+\frac{3}{4})*\frac{7}{16}+\frac{2}{3} = \frac{16}{4}*\frac{7}{16}+\frac{2}{3} = \frac{7}{4}+\frac{2}{3} = \frac{21}{12}+\frac{8}{12} = \frac{29}{12} = 2\frac{5}{12}$