1. Сократите дробь: a) $$rac{18x^6y^5}{9x^5y^8}$$ б) $$rac{4x+12y}{3x+9y}$$ в) $$rac{x^2-y^2}{3x-3y}$$

a) $$rac{18x^6y^5}{9x^5y^8} = \frac{2x}{y^3}$$ б) $$rac{4x+12y}{3x+9y} = \frac{4(x+3y)}{3(x+3y)} = \frac{4}{3}$$ в) $$rac{x^2-y^2}{3x-3y} = \frac{(x-y)(x+y)}{3(x-y)} = \frac{x+y}{3}$$