\[1\frac{1}{14}-1\frac{1}{21}=\frac{15}{14}-\frac{22}{21}=\frac{45-44}{42}=\frac{1}{42}.\]
\[\frac{8}{25}\cdot\frac{45}{12}:\frac{1}{42}\cdot\frac{5}{27}+5\frac{2}{3}=\frac{8}{25}\cdot\frac{15}{4}\cdot42\cdot\frac{5}{27}+\frac{17}{3}.\]
\[\frac{8}{25}\cdot\frac{15}{4}\cdot42\cdot\frac{5}{27}=\frac{56}{9}.\]
\[\frac{56}{9}+\frac{17}{3}=\frac{56}{9}+\frac{51}{9}=\frac{107}{9}=11\frac{8}{9}.\]
Ответ: \(11\frac{8}{9}\).