14) a2n: (a)2-10

14) $$a^{2n} : (a^5)^2 = a^{10}$$ $$a^{2n} : a^{10} = a^{10}$$ $$\frac{a^{2n}}{a^{10}} = a^{10}$$ $$a^{2n-10} = a^{10}$$ $$2n-10 = 10$$ $$2n = 10+10$$ $$2n = 20$$ $$n = \frac{20}{2}$$ $$n = 10$$

Ответ: $$n = 10$$