\[- 2 \cdot (3,5y - 2,5) + 4,5y - 1 =\]
\[= - 7y + 5 + 4,5y - 1 = - 2,5y + 4\]
\[при\ \ y = \frac{4}{5}:\]
\[- 2,5y + 4 = - 2,5 \cdot \frac{4}{5} + 4 =\]
\[= - \frac{25 \cdot 4}{10 \cdot 8} + 4 = - 2 + 4 = 2.\]