[tex] \frac{ \sqrt{2} + \sqrt{4} }{ \sqrt{7} } +\frac{ \sqrt{3} + \sqrt{7} }{ \sqrt{2} }+\frac{ \sqrt{7} + \sqrt{2} }{ \sqrt{3} }= \\
\frac{ \sqrt{2}* \sqrt{3} (\sqrt{2} + \sqrt{4})+\sqrt{7}* \sqrt{3} (\sqrt{3} + \sqrt{7})+\sqrt{2}* \sqrt{7} (\sqrt{7} + \sqrt{2})}{ \sqrt{7} \sqrt{3} \sqrt{2} }= \\
\frac{2 \sqrt{3}+2 \sqrt{2}+3 \sqrt{7} +7 \sqrt{3}+7 \sqrt{2} +2 \sqrt{7} }{\sqrt{7} \sqrt{3} \sqrt{2}} = \\ \frac{9 \sqrt{3}+9 \sqrt{2}+5 \sqrt{7} }{\sqrt{7} \sqrt{3} \sqrt{2}} [/tex]