Докажите что: √7+√2/√7-√2+√7-√2/√7+√2

Решите задачу:

$\frac{ \sqrt{7}+ \sqrt{2} }{ \sqrt{7}- \sqrt{2} } + \frac{ \sqrt{7}- \sqrt{2} }{ \sqrt{7}+ \sqrt{2} } = \frac{ (\sqrt{7}+ \sqrt{2})(\sqrt{7}+\sqrt{2} )+(\sqrt{7}- \sqrt{2} )(\sqrt{7}- \sqrt{2} ) }{ (\sqrt{7}- \sqrt{2})(\sqrt{7}+ \sqrt{2} ) } = \\ \\ =\frac{ (\sqrt{7}+ \sqrt{2})^2+(\sqrt{7}- \sqrt{2} )^2 }{ (\sqrt{7})^2- (\sqrt{2})^2 } =\frac{ 7+2 \sqrt{14}+2 +7-2 \sqrt{14}+2 }{ 7-2 } = \frac{18}{5}= 3.6$