\[\frac{8}{13} \cdot ( - 2,81) - 1,09 \cdot \frac{8}{13} =\]
\[= - \frac{8}{13} \cdot (2,81 + 1,09) = - \frac{8}{13} \cdot 3,9 =\]
\[= - \frac{8}{13} \cdot \frac{39}{10} = - \frac{4 \cdot 2 \cdot 13 \cdot 3}{13 \cdot 2 \cdot 5} = - \frac{12}{5} = - 2,4\]