已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)

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已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)由x-3y=0可得x

已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)
已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)

已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)
由x-3y=0可得x=3y
分两种情况讨论:
(1)y=0 所求无解
(2)y≠0 将x=3y代入不等式
即(6y+y)/(3y-y)^2=7/4y 其中x^2-2xy+y^2=(x-y)^2
即当y=0时,所求无解
当y≠0时 所求有无数个解 7/4y
楼主看看题目有没有错,我都晕了.

=2x+y/(x-y)²×(x-y)
=(2x+y)(x-y)/(x-y)²
=2x+y/(x-y)
∵x=3y
∴代入得7y/2y
∴解为2/7

楼主的题应该错了:试试这道题“已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)*(x-y)的值“才对嘛

-3y+x=0
-3y+x-x=-x
-3y=-x
3y=x
(2x+y)/(x^2-2xy+y^2)*(x-y)
=(2x+y)/(x-y)*(x-y)
=(2x+y)/(x-y)
=(2*3y+y)/3y-y
=6y+y/2y
=7/2