giải giúp mình với ạ

`P = (3 + sqrt5)/(sqrt2 + sqrt(3 + sqrt5)) + (3 - sqrt5)/(sqrt2 - sqrt(3 - sqrt5))`

`= (sqrt2(3 + sqrt5))/(2 + sqrt(6 + 2 sqrt5)) + (sqrt2(3 - sqrt5))/(2 - sqrt(6 - 2 sqrt5))`

`= (sqrt2(3 + sqrt5))/(2 + sqrt((sqrt5 + 1)^2)) + (sqrt2(3 - sqrt5))/(2 - sqrt((sqrt5 - 1)^2))`

`= (sqrt2(3 + sqrt5))/(2 + |sqrt5 + 1|) + (sqrt2(3 - sqrt5))/(2 - |sqrt5 - 1|)`

`=(sqrt2(3 + sqrt5))/(3 + sqrt5) + (sqrt2(3 - sqrt5))/(3 - sqrt5)`

`= sqrt2 + sqrt2`

`= 2 sqrt2`.