ta có : $\dfrac{\sqrt[]{3\sqrt[]{2} -2\sqrt[]{3} } }{\sqrt[]{3\sqrt[]{2}+2 \sqrt[]{3}} }$
`=(`$\dfrac{\sqrt[]{3\sqrt[]{2} -2\sqrt[]{3} } }{\sqrt[]{3\sqrt[]{2}+2 \sqrt[]{3}} }$ `)^2`
`=`$\dfrac{3\sqrt[]{2 }-2\sqrt[]{3} }{3\sqrt[]{2}+2 \sqrt[]{3} }$
`=`$\dfrac{\sqrt[]{3}( \sqrt[]{6} -2 )}{\sqrt[]3({\sqrt[]{6}+2) } }$
`=`$\dfrac{{\sqrt[]{6} -2 } }{{\sqrt[]{6}+2 } }$ `=`$\dfrac{{(\sqrt[]{6} -2) ²} }{2 }$
`=`$\dfrac{6-4{\sqrt[]{6}-4 } }{2 }$
`=5-2`$\sqrt{6}$
`=>`cái đấy bằng $\sqrt[]{5-2\sqrt[]{6} }$