2) $$\frac{2mn+n^2}{6m} \cdot \frac{2m}{n} = \frac{(2mn+n^2)2m}{6mn} = \frac{2m(2m+n)n}{6mn} = \frac{2m+n}{3}$$
Ответ: $$\frac{2m+n}{3}$$