Question

giải giúp a b 

Answer 1

a)\(6\sqrt[3]{81}-4\sqrt[3]{375}+3\sqrt[3]{24}\)

\(=6\sqrt[3]{3^4}-4\sqrt[3]{3.5^3}+3\sqrt[3]{3.2^3}\)

\(=6.3\sqrt[3]{3}-4.5\sqrt[3]{3}+3.2\sqrt[3]{3}=4\sqrt[3]{3}\)

b)\(\sqrt[3]{3}.\sqrt[3]{144}-\dfrac{\sqrt[3]{384}}{\sqrt[3]{3}}+2\sqrt[3]{-128}\)

\(=\sqrt[3]{432}-\sqrt[3]{\dfrac{384}{3}}+2\sqrt[3]{-2.4^3}\)

\(=\sqrt[3]{6^3.2}-\sqrt[3]{2.4^3}+2.\sqrt[3]{-2.4^3}\)

\(=6\sqrt[3]{2}-4\sqrt[3]{2}+2.-4\sqrt[3]{2}==-6\sqrt[3]{2}\)