Question

Tính giá trị của các biểu thức:

a) \(A=\sqrt[3]{8000}+\sqrt[3]{0,125}\);            b) \(B=\sqrt[3]{12^3}-\sqrt[3]{\left(-11\right)^3}\);             c) \(\left(\sqrt[3]{4}\right)^3+\left(\sqrt[3]{-5}\right)^3\).

Answer 1

a) A = \(\sqrt[3]{{8000}} + \sqrt[3]{{0,125}}\)

\(\begin{array}{l} = \sqrt[3]{{{{(20)}^3}}} + \sqrt[3]{{{{\left( {0,5} \right)}^3}}}\\ = 20 + 0,5\\ = 20,5\end{array}\)

b) B = \(\sqrt[3]{{{{12}^3}}} - \sqrt[3]{{{{( - 11)}^3}}}\)

\(\begin{array}{l}\sqrt[3]{{{{12}^3}}} - \sqrt[3]{{{{( - 11)}^3}}}\\ = 12 - ( - 11)\\ = 23\end{array}\)

c) C = \({\left( {\sqrt[3]{4}} \right)^3} + {\left( {\sqrt[3]{{ - 5}}} \right)^3}\)

\(\begin{array}{l}{\left( {\sqrt[3]{4}} \right)^3} + {\left( {\sqrt[3]{{ - 5}}} \right)^3}\\ = 4 - 5\\ =  - 1\end{array}\)