已知x+y=2,xy=2分之1,求x³y-2²y²+xy³的值
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![已知x+y=2,xy=2分之1,求x³y-2²y²+xy³的值](/uploads/image/z/2668721-41-1.jpg?t=%E5%B7%B2%E7%9F%A5x%2By%3D2%2Cxy%3D2%E5%88%86%E4%B9%8B1%2C%E6%B1%82x%26%23179%3By-2%26%23178%3By%26%23178%3B%2Bxy%26%23179%3B%E7%9A%84%E5%80%BC)
已知x+y=2,xy=2分之1,求x³y-2²y²+xy³的值
已知x+y=2,xy=2分之1,求x³y-2²y²+xy³的值
已知x+y=2,xy=2分之1,求x³y-2²y²+xy³的值
x³y-2x²y²+xy³
=xy(x²-2xy+y²)
=xy[(x²+2xy+y²)-4xy]
=xy[(x+y)²-4xy]
=2分之1×(2²-4×2分之1)
=2分之1×2
=1