2x-y=1/3,xy=3,求4x^3y-4x^2y^2+xy^3我说的是XY=3.不是2
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![2x-y=1/3,xy=3,求4x^3y-4x^2y^2+xy^3我说的是XY=3.不是2](/uploads/image/z/2519021-29-1.jpg?t=2x-y%3D1%2F3%2Cxy%3D3%2C%E6%B1%824x%5E3y-4x%5E2y%5E2%2Bxy%5E3%E6%88%91%E8%AF%B4%E7%9A%84%E6%98%AFXY%3D3.%E4%B8%8D%E6%98%AF2)
2x-y=1/3,xy=3,求4x^3y-4x^2y^2+xy^3我说的是XY=3.不是2
2x-y=1/3,xy=3,求4x^3y-4x^2y^2+xy^3
我说的是XY=3.不是2
2x-y=1/3,xy=3,求4x^3y-4x^2y^2+xy^3我说的是XY=3.不是2
4x^3y-4x^2y^2+xy^3=xy(4x^2-4xy+y^2)=xy(2x-y)^2=3*(1/3^2)=1/3
2X-Y=1/3
XY=2
4X^3y-3x^2y^2+xy^3
= 4X^3y-4x^2y^2+xy^3 + x^2y^2
= xy (4X^2-4xy+y^2) + x^2y^2
= xy(2x-y)^2 + x^2y^2
= 2 * (1/3)^2 + 2^2
= 2/9 +4
= 38/9