Question

[Sách Giáo Khoa]

Chứng minh các đẳng thức sau :

a) \(\sqrt[3]{a^3b}=a\sqrt[3]{b}\)

b) \(\sqrt[3]{\dfrac{a}{b^2}}=\dfrac{1}{3}\sqrt[3]{ab};\left(b\ne0\right)\)

Answer 1

[Nguyen Thuy Hoa]

a) \(\sqrt[3]{a^3b}=\sqrt[3]{a^3}\sqrt[3]{b}=a\sqrt[3]{b}\)

b) \(\sqrt[3]{\dfrac{a}{b^2}}=\sqrt[3]{\dfrac{ab}{b^3}}=\dfrac{\sqrt[3]{ab}}{\sqrt[3]{b^3}}=\dfrac{1}{b}\sqrt[3]{ab}\)