Question

evaluate x^2+y^2......

Answer 1

In first case
(I)
$x = (2 + \sqrt 5) y2 + (2 + \sqrt{5} )y2$
$x = \frac{2 + \sqrt{5 } + 2 - \sqrt{5} }{2}$

$x = \frac{4}{2}$
$x = 2$

In second case
(ii)

$y = \frac{2 + \sqrt{5} }{2} + \frac{2 - \sqrt{5} }{2}$
$y = \frac{2 + \sqrt{5} + 2 - \sqrt{5} } {2}$

$y = \frac{4}{2}$
$y = 2$

$now \: on \: evaluting$
${x}^{2} + {y}^{2} = {2}^{2} + {2}^{2}$
$= 4 + 4 = 8$