Сократите дробь: a) $$rac{3ab}{12ac}$$; б) $$rac{-4ax}{6bx^2}$$

a) $$rac{3ab}{12ac} = rac{3 cdot a cdot b}{3 cdot 4 cdot a cdot c} = rac{b}{4c}$$

б) $$rac{-4ax}{6bx^2} = rac{-2 cdot 2 cdot a cdot x}{2 cdot 3 cdot b cdot x cdot x} = rac{-2a}{3bx}$$