Question

If x =(2+root 5) ,find the value of x+1/x

Answer 1

Answer:

$x = 2 + \sqrt{5} \\ 1 \div x = 1 \div 2 + \sqrt{5} = 2 - \sqrt{5} \div - 1 = \sqrt{5} - 2 \\ 2 + \sqrt{5} + \sqrt{5} - 2 = 2 \sqrt{5}$