13. Вычислите: a) $$\frac{18^6 \cdot 2^6}{20^6}$$;

a) $$\frac{18^6 \cdot 2^6}{20^6} = \frac{(18 \cdot 2)^6}{20^6} = \frac{36^6}{20^6} = (\frac{36}{20})^6 = (\frac{9}{5})^6 = (1.8)^6 = 34.012224$$