3) Упрости выражения: 1. \(\sqrt[3]{27x^6}\); 2. \(\sqrt[4]{16x^8y^{12}}\); 3. \(\sqrt[6]{64x^{18}y^6}\); 4. \(\sqrt[5]{243a^{15}b^5}\); 5. \(\sqrt[4]{\frac{16x^{12}}{81y^4}}\); 6. \(\sqrt[3]{\frac{216a^9}{27b^3}}\).

1. \(\sqrt[3]{27x^6}=3x^2\).
2. \(\sqrt[4]{16x^8y^{12}}=2x^2y^3\).
3. \(\sqrt[6]{64x^{18}y^6}=2x^3y\).
4. \(\sqrt[5]{243a^{15}b^5}=3a^3b\).
5. \(\sqrt[4]{\frac{16x^{12}}{81y^4}}=\frac{2x^3}{3y}\).
6. \(\sqrt[3]{\frac{216a^9}{27b^3}}=\sqrt[3]{\frac{8a^9}{b^3}}=\frac{2a^3}{b}\).

Ответ: 1) \(3x^2\); 2) \(2x^2y^3\); 3) \(2x^3y\); 4) \(3a^3b\); 5) \(\frac{2x^3}{3y}\); 6) \(\frac{2a^3}{b}\).