Question

Tìm x, biết:

a) x³ = –27;               b) \(x^3=\dfrac{64}{125}\);              c) \(\sqrt[3]{x}=8\);              d) \(\sqrt[3]{x}=-0,9\).

Answer 1

a) x³ = - 27

x = \(\sqrt[3]{{ - 27}} =  - 3\)

b) x³ = \(\frac{{64}}{{125}}\)

x = \(\sqrt[3]{{\frac{{64}}{{125}}}} = \frac{4}{5}\)

c) \(\sqrt[3]{x} = 8\)

x = 8³ = 512

d) \(\sqrt[3]{x} =  - 0,9\)

x = (-0,9)³ = - 0,729