Ответ:
Числитель:
\[6\dfrac{2}{3}+2\dfrac{4}{15}+5\dfrac{1}{2}=\dfrac{100}{15}+\dfrac{34}{15}+\dfrac{165}{30}=\dfrac{67}{6}.\]
\[\dfrac{67}{6}:\dfrac{1}{15}=\dfrac{335}{2},\qquad 30:\dfrac{5}{28}=168.\]
\[\left(\dfrac{335}{2}-168\right):2\dfrac{3}{4}=\dfrac{-1}{2}:\dfrac{11}{4}=-\dfrac{2}{11}.\]
Знаменатель:
\[5\cdot\dfrac{4}{5}-\dfrac{3}{5}\cdot\dfrac{5}{22}=4-\dfrac{3}{22}=\dfrac{85}{22}.\]
\[\dfrac{85}{22}:42\dfrac{1}{2}=\dfrac{85}{22}:\dfrac{85}{2}=\dfrac{1}{11}.\]
\[\left(-\dfrac{2}{11}\right):\dfrac{1}{11}=-2.\]
Ответ: \(-2\).
