Выполни умножение

1. \(\cfrac{xy+y^2}{48x} \cdotp \cfrac{6x}{x+y}\) \(=\) \(\cfrac{y(x+y)}{48x} \cdotp \cfrac{6x}{x+y} \) \(=\) [ ].
2. \(\cfrac{a^2-64b^2}{5a^2} \cdotp \cfrac{a}{5a-40b}\) \(=\) [ ] \(=\) [ ].
3. \((a+9) \cdotp \cfrac{a}{3a+27}= \cfrac{a+9}{1} \cdot\) [ ] \(=\) [ ].
4. \(\cfrac{8}{m^2-14mn+49n^2} \cdotp (m^2-49n^2)\) \(=\) [ ].