Решите 3 примера!!! упростите

1) $\frac{2ab+4b}{3a}* \frac{6 a^{2} }{ a^{2}b-4b } = \frac{2b(a+2)}{3a}* \frac{6 a^{2} }{b(a-2)(2+2)}= \frac{4ab}{b(a-2)} = \frac{4a}{a-2}$
2) $\frac{ m^{2}- n^{2} }{3mn} : \frac{ m^{2}+2mn+ n^{2} }{6 m^{2} n^{2} } = \frac{(m-n)(m+n)}{3mn}* \frac{6 m^{2} n^{2} }{(m+n)(m+n)} = \frac{2mn(m-n)}{m+n}$
3) $\frac{ x^{2}- y^{2} }{ x^{2} } : ( \frac{x+y}{x}) ^{2} = \frac{(x-y)(x+y)}{ x^{2} } * \frac{ x^{2} }{(x+y)(x+y)}= \frac{x-y}{x+y}$