Answer:
[tex] - \frac{1}{2} ( \frac{4}{5} - 8y) \\ = - \frac{4}{10} + \frac{8y}{2} \\ = - \frac{2}{5} + 4y \\ = \frac{ - 2 + 5 \times 4y}{5} = \frac{ - 2 + 20y}{5} \\ - 2 + 20y = 0 \\ 20y = 2 \\ y = \frac{1}{10} [/tex]
