Выполните действия: a) $$\frac{63a^2b}{c} \cdot \frac{18a^2b}{c^2}$$ b) $$\frac{3x+6}{x+3} \cdot \frac{x^2-9}{x^2-4}$$ v) $$\left(-\frac{2a^2}{b}\right)^3$$ gr) $$3ab \cdot \frac{a^2}{b}$$

a) $$\frac{63a^2b}{c} \cdot \frac{18a^2b}{c^2} = \frac{63 \cdot 18 \cdot a^4b^2}{c^3} = \frac{1134a^4b^2}{c^3}$$ b) $$\frac{3x+6}{x+3} \cdot \frac{x^2-9}{x^2-4} = \frac{3(x+2)}{x+3} \cdot \frac{(x-3)(x+3)}{(x-2)(x+2)} = \frac{3(x-3)}{x-2}$$ v) $$\left(-\frac{2a^2}{b}\right)^3 = -\frac{8a^6}{b^3}$$ gr) $$3ab \cdot \frac{a^2}{b} = 3a^3$$