Question

If a=2-√5/2+√5 and b=2+√5/2-√5 find (a+b)³

Answer 1

64

Explanation:

Given :

• a = 2 - √5/2 + √5
• b = 2 + √5/2 - √5

Evaluating (a + b)³ :

• (2 - √5/2 + √5 + 2 + √5/2 - √5)³
• (2 + 2 - √5/2 + √5/2 + √5 - √5)³
• (4)³
• 64

Answer 2

Explanation:

really ? you need help here ... - that means you did not even look at it once ...

a = 2 - sqrt(5)/2 + sqrt(5)

b = 2 + sqrt(5)/2 - sqrt(5)

a + b = 2 + 2 = 4 (the rest add up to 0)

(a+b)³ = 4³ = 64