求这道数学题的解法.(初三数学)

x+y=√2007
xy=1/2(2007-2005)=1

所以x²-xy+y²
=(x+y)²-3xy
=2007-3
=2004

x/y+y/x
=(x²+y²)/xy
=x²+y²
=(x+y)²-2xy
=2007-2
=2005

x+y=√2007,
xy=1/2,

1)
x^2-xy+y^2
=(x+y)^2-3xy
=2007-3/2
=2005又1/2

2）x/y+y/x
=(x^2+y^2)/xy
=[(x+y)^2-2xy]/xy
=(2007-3)/(3/2)
=1336

1.不是
直接把x，y带进去求，二次项还都能消了

2004

2.x/y+y/x=(x²+y²)/xy
然后直接代入x，y

2005