Ответ:
\[6:\frac{18}{23}=6\cdot\frac{23}{18}=\frac{23}{3}.\]
\[\frac{3}{14}-4\frac{13}{28}=\frac{6}{28}-\frac{125}{28}=-\frac{119}{28}=-\frac{17}{4}.\]
\[2\frac{2}{3}\cdot\left(-\frac{17}{4}\right)=\frac{8}{3}\cdot\left(-\frac{17}{4}\right)=-\frac{34}{3}.\]
\[\frac{23}{3}-\frac{34}{3}=-\frac{11}{3}.\]
Ответ: \(-\frac{11}{3}\).
