Кыскарткыла:
1) $$√{n^8} = (n^8)^{\frac{1}{2}} = n^{\frac{8}{2}} = n^4$$
2) $$√{x^{12}} = (x^{12})^{\frac{1}{2}} = x^{\frac{12}{2}} = x^6$$
3) $$√{a^{14}} = (a^{14})^{\frac{1}{2}} = a^{\frac{14}{2}} = a^7$$
4) $$√{b^6} = (b^6)^{\frac{1}{2}} = b^{\frac{6}{2}} = b^3$$
Ответ: 1) $$n^4$$; 2) $$x^6$$; 3) $$a^7$$; 4) $$b^3$$