[tex]2 \sqrt[3]{6}= \sqrt[3]{6*2^3} = \sqrt[3]{6*8}= \sqrt[3]{48} [/tex]
[tex]3 \sqrt[3]{3}= \sqrt[3]{3*3^3}= \sqrt[3]{3*27}= \sqrt[3]{81} [/tex]
[tex] 2\sqrt[3]{6}\ \textless \ 3\sqrt[3]{3} [/tex]
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[tex] 2\sqrt[3]{6}*3 \sqrt[3]{3}=2*3 \sqrt[3]{6*3}=6 \sqrt[3]{18} [/tex]