(4)=3^(1/2)×9^(1/3)×27^(1/4)=3^(1/2)×(3²)^(1/3)×(3³)^(1/4)=3^(1/2)×3^(2/3)×3^(3/4)=3^(1/2+2/3+3/4)=3^(23/12).
