\[\left( 1\frac{1}{2} - \frac{1}{3} \right)\ :\left( - \frac{1}{6} \right) < 10,5\ :( - 2,1)\]
\[\left( 1\frac{3}{6} - \frac{2}{6} \right)\ :\left( - \frac{1}{6} \right) < - \frac{105}{10} \cdot \frac{10}{21}\]
\[1\frac{1}{6} \cdot ( - 6) < - 5\]
\[- \frac{7}{6} \cdot 6 < - 5\]
\[- 7 < - 5 \Longrightarrow верно.\]