Question

a=2-√5/2+√5, b=2+√5/2-√5 find (a+b)³

Answer 1

So,a+b = 2-✓5/2+✓5+2 +✓5/2-✓5
Then a+b = 4
cube at both sides
(a+b)^3 = 4^3
(a+b)^3 = 64