Сократите дробь: a) $$rac{39x^3y}{26x^2y^2}$$, б) $$rac{5y}{y^2 - 2y}$$, в) $$rac{3a - 3b}{a^2 - b^2}$$

a) $$rac{39x^3y}{26x^2y^2} = rac{3 cdot 13 cdot x^2 cdot x cdot y}{2 cdot 13 cdot x^2 cdot y cdot y} = \frac{3x}{2y}$$ б) $$\frac{5y}{y^2 - 2y} = \frac{5y}{y(y - 2)} = \frac{5}{y - 2}$$ в) $$\frac{3a - 3b}{a^2 - b^2} = \frac{3(a - b)}{(a - b)(a + b)} = \frac{3}{a + b}$$