10-12номера. Помогите пожалуйста! Много балов

Решите задачу:

$10.\\\\2\frac{6}{7}:\frac{5}{6}-\frac{9}{14}=2\frac{11}{14}\\\\1)2\frac{6}{7}:\frac{5}{6}=\frac{20}{7}*\frac{6}{5}=\frac{20*6}{7*5}=\frac{24}{7}\\\\2)\frac{24}{7}-\frac{9}{14}=\frac{24*2-9*1}{14}=\frac{39}{14}=2\frac{11}{14}$

$11.\\\\2\frac{1}{4}:1\frac{4}{11}-\frac{3}{8}:\frac{7}{8}=1\frac{31}{140}\\\\1)2\frac{1}{4}:1\frac{4}{11}=\frac{9}{4}:\frac{15}{11}=\frac{9}{4}*\frac{11}{15}=\frac{33}{20}\\\\ 2)\frac{3}{8}:\frac{7}{8}=\frac{3*8}{8*7}=\frac{3}{7}\\\\3)\frac{33}{20}-\frac{3}{7}=\frac{33*7-3*20}{140}=\frac{171}{140}=1\frac{31}{140}$

$12.\\\\(3\frac{1}{6}-5\frac{1}{6}:4\frac{2}{15})*\frac{3}{92}=\frac{1}{16}\\\\1)5\frac{1}{6}:4\frac{2}{15}=\frac{31}{6}:\frac{62}{15}=\frac{31*15}{6*62}=\frac{5}{4}\\\\2)3\frac{1}{6}-\frac{5}{4}=\frac{19}{6}-\frac{5}{4}=\frac{19*2-5*3}{12}=\frac{23}{12}\\\\3)\frac{23}{12}*\frac{3}{92}=\frac{23*3}{12*92}=\frac{1}{16}$