We have x = sqrt(3 - sqrt 5) + sqrt(3 + sqrt 5).

x^2 = [sqrt(3 - sqrt 5) + sqrt(3 + sqrt 5)]^2

=> (3 - sqrt 5) + (3 + sqrt 5) + 2*sqrt(3 - sqrt 5)*sqrt(3 + sqrt 5)

=> 6 + 2*sqrt(9 - 5)

=> 6 + 2*2

=> 10

**This proves that x^2 = 10**

We have x = sqrt(3 - sqrt 5) + sqrt(3 + sqrt 5).

x^2 = [sqrt(3 - sqrt 5) + sqrt(3 + sqrt 5)]^2

=> (3 - sqrt 5) + (3 + sqrt 5) + 2*sqrt(3 - sqrt 5)*sqrt(3 + sqrt 5)

=> 6 + 2*sqrt(9 - 5)

=> 6 + 2*2

=> 10

**This proves that x^2 = 10**