Đáp án + Giải thích các bước giải:
`E=sqrt((3-sqrt5)/(3+sqrt5))-sqrt((3+sqrt5)/(3-sqrt5))`
`=sqrt((3-sqrt5)^2/((3+sqrt5)(3-sqrt5)))-sqrt((3+sqrt5)^2/((3-sqrt5)(3+sqrt5)))`
`=sqrt((3-sqrt5)^2/(4))-sqrt((3+sqrt5)^2/(4))`
`=sqrt((3-sqrt5)^2)/(2)-sqrt((3+sqrt5)^2)/(2)`
`=(|3-sqrt5|)/(2)-|3+sqrt5|/(2)`
`=(3-sqrt5)/(2)-(3+sqrt5)/(2)`
`=((3-sqrt5)-(3+sqrt5))/(2)`
`=(-2sqrt5)/(2)`
`=-sqrt5`
`F=(1/(3-sqrt5)-1/(3+sqrt5)):(5-sqrt5)/(sqrt5-1)`
`=(3+sqrt5-3+sqrt5)/((3-sqrt5)(3+sqrt5)):(sqrt5(sqrt5-1))/(sqrt5-1)`
`=(2sqrt5)/(3^2-(sqrt5)^2):(sqrt5(sqrt5-1))/(sqrt5-1)`
`=(2sqrt5)/(4):sqrt5`
`=(sqrt5)/(2). 1/sqrt5`
`=1/2`
