写成分数指数
=[25^(1/3)-125^(1/2)]÷25^(1/4)
=[5^(2/3)-5^(3/2)]÷5^(1/2)
=5^(2/3)÷5^(1/2)-5^(3/2)÷5^(1/2)
=5^(2/3-1/2)-5^(3/2-1/2)
=5^(1/6)-5