$a)\left(6\frac{1}{2}-4\frac{7}{10}\right):\left(4-2\frac{1}{5}\right)=\left(6\frac{5}{10}-4\frac{7}{10}\right):\left(3\frac{5}{5}-2\frac{1}{5}\right)=\left(5\frac{15}{10}-4\frac{7}{10}\right):1\frac{4}{5}=1\frac{8}{10}:1\frac{4}{5}=1\frac{4}{5}:1\frac{4}{5}=1$  

$b)\left(8\frac{1}{8}-4\frac{3}{4}\right)\cdot \left(5-\frac{1}{3}\right)=\left(7\frac{9}{8}-4\frac{6}{8}\right)\cdot 4\frac{2}{3}=3\frac{3}{8}\cdot \frac{14}{3}=\frac{{\sout{27}}^9}{{\sout{8}}^4}\cdot \frac{{\sout{14}}^7}{{\sout{3}}^1}=\frac{63}{4}=15\frac{3}{4}$ $b)\left(8\frac{1}{8}-4\frac{3}{4}\right)\cdot \left(5-\frac{1}{3}\right)=\left(7\frac{9}{8}-4\frac{6}{8}\right)\cdot 4\frac{2}{3}=3\frac{3}{8}\cdot \frac{14}{3}=\frac{{\sout{27}}^9}{{\sout{8}}^4}\cdot \frac{{\sout{14}}^7}{{\sout{3}}^1}=\frac{63}{4}=15\frac{3}{4}$  

$c)\left(4\frac{4}{5}-1\frac{1}{3}\right):4=\left(4\frac{12}{15}-1\frac{5}{15}\right):4=3\frac{7}{15}\cdot \frac{1}{4}=\frac{{\sout{52}}^{13}}{15}\cdot \frac{1}{{\sout{4}}^1}=\frac{13}{15}$  

$d)\left(3\frac{5}{7}-1\frac{11}{14}\right)\cdot 4\frac{2}{3}=\left(2\frac{12}{7}-1\frac{11}{14}\right)\cdot \frac{14}{3}=\left(2\frac{24}{14}-1\frac{11}{14}\right)\cdot \frac{14}{3}=1\frac{13}{14}\cdot \frac{14}{3}=\frac{{\sout{27}}^9}{{\sout{14}}^1}\cdot \frac{{\sout{14}}^1}{{\sout{3}}^1}=9$  

$e)\frac{1}{6}:\left(5\frac{2}{3}-4\frac{1}{2}\right)=\frac{1}{6}:\left(\frac{17}{3}-\frac{9}{2}\right)=\frac{1}{6}:\left(\frac{34}{6}-\frac{27}{6}\right)=\frac{1}{6}:\frac{7}{6}=\frac{1}{{\sout{6}}^1}\cdot \frac{{\sout{6}}^1}{7}=\frac{1}{7}$  

$f)1\frac{4}{7}:22\frac{1}{5}+3\frac{1}{4}\cdot \frac{1}{26}=\frac{11}{7}:\frac{11}{5}+\frac{{\sout{13}}^1}{4}\cdot \frac{1}{{\sout{26}}^2}=\frac{{\sout{11}}^1}{7}\cdot \frac{5}{{\sout{11}}^1}+\frac{1}{8}=\frac{5}{7}+\frac{1}{8}=\frac{40}{56}+\frac{7}{56}=\frac{47}{56}$