б) $$ \frac{8y-5}{7y} - \frac{2y-1}{7y} - \frac{10-y}{7y} = \frac{8y-5-2y+1-10+y}{7y} = \frac{7y-14}{7y} = \frac{y-2}{y} $$
Ответ:$$\frac{y-2}{y}$$