If x - 1/x = 5 √2 then find the value of ( x + 1/x )

⇒ If x - \(\frac{1}{x}\) = a then x + \(\frac{1}{x}\) = \(\sqrt {a^2 + 4}\)

Here,

x - \(\frac{1}{x}\) = 5\(\sqrt{2}\), then 

⇒ x + \(\frac{1}{x}\) = \(\sqrt {(5\sqrt{2})^2 + 4}\) = \(\sqrt{54}\)