2) Сократите дроби: а) (2x − 2b)/(3(x − b)); б) (5a − 10y)/(2a − 4y); в) (7x − 21y)/(35xy); г) (m − 3n)/(m² − 3mn).

1. \(\dfrac{2x-2b}{3(x-b)}=\dfrac{2(x-b)}{3(x-b)}=\dfrac{2}{3}\).
2. \(\dfrac{5a-10y}{2a-4y}=\dfrac{5(a-2y)}{2(a-2y)}=\dfrac{5}{2}\).
3. \(\dfrac{7x-21y}{35xy}=\dfrac{7(x-3y)}{35xy}=\dfrac{x-3y}{5xy}\).
4. \(\dfrac{m-3n}{m^2-3mn}=\dfrac{m-3n}{m(m-3n)}=\dfrac{1}{m}\).

Ответ: а) \(\dfrac{2}{3}\); б) \(\dfrac{5}{2}\); в) \(\dfrac{x-3y}{5xy}\); г) \(\dfrac{1}{m}\).