3. Вычислите: а) $$\frac{6^8 \cdot 6^{12}}{6^{18}}$$; б) $$\frac{4^6 \cdot 64}{16^4}$$.

a) $$\frac{6^8 \cdot 6^{12}}{6^{18}} = \frac{6^{8+12}}{6^{18}} = \frac{6^{20}}{6^{18}} = 6^{20-18} = 6^2 = 36$$ б) $$\frac{4^6 \cdot 64}{16^4} = \frac{4^6 \cdot 4^3}{(4^2)^4} = \frac{4^{6+3}}{4^{2\cdot4}} = \frac{4^9}{4^8} = 4^{9-8} = 4^1 = 4$$ Ответ: а) 36; б) 4