[tex] 6^{\frac{1}{2}} + 6^{\frac{3}{2}} = 6^{\frac{1}{2}} + 6^{\frac{1}{2}}*6^{\frac{1}{2}}*6^{\frac{1}{2}}= 6^{\frac{1}{2}}(1+6^{\frac{1}{2}}*6^{\frac{1}{2}})=6^{\frac{1}{2}}(1+6^{\frac{2}{2}}) = 7*6^{\frac{1}{2}} = 7\sqrt{6} [/tex]
