4. Упростите: a) $$\frac{x^7 \cdot x^6}{(x^2)^4}$$ б) $$\frac{a^{12} \cdot (a^2)^4}{(a^3)^6}$$

a) $$\frac{x^7 \cdot x^6}{(x^2)^4} = \frac{x^{7+6}}{x^{2\cdot4}} = \frac{x^{13}}{x^8} = x^{13-8} = x^5$$ б) $$\frac{a^{12} \cdot (a^2)^4}{(a^3)^6} = \frac{a^{12} \cdot a^{2\cdot4}}{a^{3\cdot6}} = \frac{a^{12} \cdot a^8}{a^{18}} = \frac{a^{12+8}}{a^{18}} = \frac{a^{20}}{a^{18}} = a^{20-18} = a^2$$