27) $$\frac{4}{49}k^2 - \frac{1}{36}p^2 = (\frac{2}{7}k - \frac{1}{6}p)(\frac{2}{7}k + \frac{1}{6}p)$$
Ответ: $$(\frac{2}{7}k-\frac{1}{6}p)(\frac{2}{7}k+\frac{1}{6}p)$$