Question

answer this question​

Answer 1

your answer is 10 + root 5 plz verify

Answer 2

${\huge {\mathfrak {Answer :-}}}$

➡️ We have, x = 2 + $\sqrt {5}$

➡️ So, 1/x = 1/(2 + $\sqrt {5}$)

= - (2 - $\sqrt {5}$) / 1

= $\sqrt {5}$ - 2

➡️ So, x + 1/x = (2 + $\sqrt {5}$) + ($\sqrt {5}$ - 2)

= 2$\sqrt {5}$

➡️ (x + 1/x)^2 = x^2 + 1/x^2 + 2

Or, (2$\sqrt {5}$) = x^2 + 1/x^2 + 2

Or, 20 = x^2 + 1/x^2 + 2

Or, x^2 + 1/x^2 = 18. ⬅️

$<b>$ That's it..