Question

$1/2+\sqrt{5} + 1/2-\sqrt{5}$

Answer 1

1/(2+√5) + 1/(2-√5) = ((2-√5) +(2+√5)) / ((2-√5)*(2+√5) ) =

= ((2-√5 +2+√5)) / ((2-√5)*(2+√5) ) = 4/(4 - 5) = 4/-1 = - 4