Сокращение дробей

1. а) $$rac{14x^4y}{49x^3y^2} = rac{2x}{7y}$$
2. б) $$rac{5x}{x^2+3x} = rac{5x}{x(x+3)} = rac{5}{x+3}$$
3. в) $$rac{x^2-y^2}{2x-2y} = rac{(x-y)(x+y)}{2(x-y)} = rac{x+y}{2}$$
4. г) $$rac{x^2-16}{x^2-8x+16} = rac{(x-4)(x+4)}{(x-4)^2} = rac{x+4}{x-4}$$