∵a³－b³=﹙a-b﹚﹙a²+ab+b²﹚
∴(三次根号4+三次根号6+三次根号9)分之一
=1/﹛﹙2^(2/3)+﹙2×3﹚^(1/3)+3^(2/3)﹜
=﹙3^(2/3)－2^(2/3)﹚／﹙3-2﹚
=3^(2/3)－2^(2/3﹚