已知2x^2-3xy+y^2=0(xy不等于0),则xy+yx的值是?
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![已知2x^2-3xy+y^2=0(xy不等于0),则xy+yx的值是?](/uploads/image/z/1031315-59-5.jpg?t=%E5%B7%B2%E7%9F%A52x%5E2-3xy%2By%5E2%3D0%EF%BC%88xy%E4%B8%8D%E7%AD%89%E4%BA%8E0%EF%BC%89%2C%E5%88%99xy%2Byx%E7%9A%84%E5%80%BC%E6%98%AF%3F)
已知2x^2-3xy+y^2=0(xy不等于0),则xy+yx的值是?
已知2x^2-3xy+y^2=0(xy不等于0),则xy+yx的值是?
已知2x^2-3xy+y^2=0(xy不等于0),则xy+yx的值是?
依据十字相乘法分解因式:
1 -1
2 -1
------------------------
-2-1=-3
因此:
(x-y)(2x-y)=0
所以:
x=y或者2x=y
因此:
(x/y) + (y/x)
=1+1
=2
或者:
(x/y) + (y/x)
=1/2 + 2
=5/2
综上:
(x/y) + (y/x)=2或者5/2
2x^2-2xy-xy+y^2=2x(x-y)-y(x-y)=(2x-y)(x-y)=0感觉解不出来x,y具体乘积值啊,你要是求x,y比值还是可以解的,即:
x/y=1或1/2,然后求解可以了