If x =
and y =
, then x + y + xy =
Given x = √5 +√3 / √5 - √3 , y =√5 - √3 / √5 + √3
X= 
Y = 
Xy = 42 - √152 = 16 – 15 = 1
So,
X + y+ xy = 4+√15 + 4 - √15 + 1 = 9.
14
If x = and y =, then x + y + xy =
Given x = √5 +√3 / √5 - √3 , y =√5 - √3 / √5 + √3
X=
Y =
Xy = 42 - √152 = 16 – 15 = 1
So,
X + y+ xy = 4+√15 + 4 - √15 + 1 = 9.