\[- 6 \cdot (0,5x - 1,5) - 4,5x - 8 =\]
\[= - 3x + 9 - 4,5x - 8 = - 7,5x + 1\]
\[при\ \ \ x = \frac{2}{3}:\]
\[- 7,5x + 1 = - 7,5 \cdot \frac{2}{3} + 1 = - \frac{75 \cdot 2}{10 \cdot 3} + 1 =\]
\[= - 5 + 1 = - 4.\]