3m +1 3m + 9n в) -:-; 3m2-27n2 2+6m

в) $$\frac{3m+1}{3m^2-27n^2} : \frac{3m+9n}{2+6m} = \frac{3m+1}{3(m^2-9n^2)} : \frac{3(m+3n)}{2(1+3m)} = \frac{(3m+1) \cdot 2(1+3m)}{3(m-3n)(m+3n) \cdot 3(m+3n)} = \frac{2(3m+1)^2}{9(m-3n)(m+3n)^2}$$

Ответ: $$\frac{2(3m+1)^2}{9(m-3n)(m+3n)^2}$$