根号(2/3)-4根号216+42根号(1/6)
=1/3根号6-24根号6+42*1/6根号6
=1/3根号6-24根号6+7根号6
=-16又2/3根号6
解:
√(2/3)-4√216+42√(1/6)
=[√(2/3)][(√3)/(√3)]-4√(6^3)216+42√(1/6)[(√6)/(√6)]
=(1/3)√6-4×6√6+(42√6)/6
=(1/3)√6-24√6+7√6
=[(1/3)-24+7]√6
=-(50√6)/3
√(2/3)-4√216+√(1/6)=√6/9-24√6+7√6=-(152/9)√6