根号18/根号2+根号2
=3根号2/根号2+根号2
=3+根号2
[(1+(根号3-根号5)][1-(根号3-根号5)]
=1-(根号3-根号5)平方
=1-(3-2根号15+5)
=-7+2根号15
4x平方=49/25
2x=7/5
x=7/10
根号18/根号2+根号2
=3根号2/根号2+根号2
=3+根号2
[(1+(根号3-根号5)][1-(根号3-根号5)]
=1-(根号3-根号5)平方
=1-(3-2根号15+5)
=-7+2根号15
4x平方=49/25
2x=7/5
x=7/10