Step-by-step explanation:
[tex] \frac{1}{ \sqrt{5} + \sqrt{2} } \\ = \frac{1}{ \sqrt{5} + \sqrt{2} } \times \frac{\sqrt{5} - \sqrt{2} }{ \sqrt{5} - \sqrt{2} } \\ \\ = \frac{ \sqrt{5} - \sqrt{2} }{ {( \sqrt{5)} }^{2} - {( \sqrt{2)} }^{2} } \\ \\ = \frac{ \sqrt{5} - \sqrt{2} }{5 - 2 } \\ \\ = \frac{ \sqrt{5} - \sqrt{2} }{3} [/tex]
