第9章 9.1

(1)

$\sqrt[3]{-125} = \sqrt[3]{(-5)^3} = -5$

(2)

$\sqrt[5]{-32} = \sqrt[5]{(-2)^5} = -2$

(3)

$\sqrt[4]{(-6)^4} = 6$

(4)

$\sqrt[4]{16^3} = \sqrt[4]{8^4} = 8$

(5)

$\sqrt[4]{(-81)^2} = \sqrt[4]{9^4} = 9$

(6)

$\sqrt[3]{8^5} = \sqrt[3]{32^3} = 32$

(7)

$\sqrt[3]{\dfrac{27}{64}} = \sqrt[3]{\dfrac{3^3}{4^3}} = \dfrac{3}{4}$

(8)

$\sqrt[4]{\dfrac{4^3}{18^2}} = \sqrt[4]{\dfrac{2^6}{2^2 3^4}} = \sqrt[4]{\dfrac{2^4}{3^4}} = \dfrac{2}{3}$