Đáp án:
`sqrt5`
Giải thích các bước giải:
`sqrt(2/(3-sqrt5))+2/(sqrt5+1)`
`=sqrt(4/(6-2sqrt5))+(2(sqrt5-1))/((sqrt5+1)(sqrt5-1))`
`=sqrt(4/(5-2sqrt5+1))+(2(sqrt5-1))/4`
`=sqrt(4/((sqrt5-1)^2))+(sqrt5-1)/2`
`=(sqrt4)/(sqrt((sqrt5-1)^2))+(sqrt5-1)/2`
`=2/(sqrt5-1)+(sqrt5-1)/2`
`=(2(sqrt5+1))/((sqrt5-1)(sqrt5+1))+(sqrt5-1)/2`
`=(2(sqrt5+1))/4+(sqrt5-1)/2`
`=(sqrt5+1)/2+(sqrt5-1)/2=(sqrt5+1+sqrt5-1)/2`
`=(2sqrt5)/2=sqrt5`