1 19-(2-)=20020

Решим пример:

$$\begin{aligned}
19\frac{1}{2} : \left(3\frac{1}{2} - 1\frac{11}{20}\right) - \frac{111}{200} + \frac{3}{20} = \frac{39}{2} : \left(\frac{7}{2} - \frac{31}{20}\right) - \frac{111}{200} + \frac{3}{20} = \frac{39}{2} : \left(\frac{70}{20} - \frac{31}{20}\right) - \frac{111}{200} + \frac{3}{20} = \frac{39}{2} : \frac{39}{20} - \frac{111}{200} + \frac{3}{20} = \frac{39}{2} \cdot \frac{20}{39} - \frac{111}{200} + \frac{3}{20} = 10 - \frac{111}{200} + \frac{30}{200} = 10 - \frac{81}{200} = 9\frac{200}{200} - \frac{81}{200} = 9\frac{119}{200}
\end{aligned}$$

Ответ:$$9\frac{119}{200}$$