Giải thích các bước giải:
`A=sqrt(3+sqrt5)+sqrt(3-sqrt5)`
`sqrt2A=sqrt(6+2sqrt5)+sqrt(6-2sqrt5)`
`sqrt2A=sqrt(5+2sqrt5+1)+sqrt(5-2sqrt5+1)`
`sqrt2A=sqrt((sqrt5+1)^2)+sqrt((sqrt5-1)^2)`
`sqrt2A=|sqrt5+1|+|sqrt5-1|`
`sqrt2A=sqrt5+1+sqrt5-1=2sqrt5`
`A=(2sqrt5)/(sqrt2)=(2sqrt5 . sqrt2)/(sqrt2 . sqrt2)`
`A=(2sqrt10)/2=sqrt10`
Vậy `sqrt(3+sqrt5)+sqrt(3-sqrt5)=sqrt10`