\[4x + 3y\ \ \ при\ \ \ x = - \frac{3}{4};\ \ y = - \frac{1}{6}:\]
\[4 \cdot \left( - \frac{3}{4} \right) + 3 \cdot \left( - \frac{1}{6} \right) = - \frac{4 \cdot 3}{4} - \frac{3}{6} =\]
\[= - 3 - \frac{1}{2} = - \frac{6}{2} - \frac{1}{2} = - \frac{7}{2} = - 3,5.\]