\[18 \cdot \left( \frac{1}{9} \right)^{2} - 20 \cdot \frac{1}{9} = 18 \cdot \frac{1}{81} - \frac{20}{9} =\]
\[= \frac{2}{9} - \frac{20}{9} = - \frac{18}{9} = - 2.\]