已知xy=-1,求3xy^2(x-x^3y^2-1/2x^2y)的值

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已知xy=-1,求3xy^2(x-x^3y^2-1/2x^2y)的值已知xy=-1,求3xy^2(x-x^3y^2-1/2x^2y)的值已知xy=-1,求3xy^2(x-x^3y^2-1/2x^2y)

已知xy=-1,求3xy^2(x-x^3y^2-1/2x^2y)的值
已知xy=-1,求3xy^2(x-x^3y^2-1/2x^2y)的值

已知xy=-1,求3xy^2(x-x^3y^2-1/2x^2y)的值
3xy²(x-x³y²-1/2x²y)
=3x²y²-3x⁴y⁴-(3/2)x³y³
=3(xy)²-3(xy)⁴-(3/2)*(xy)³
=3×(-1)²-3×(-1)⁴-(3/2)×(-1)³
=3-3+3/2
=3/2

3xy^2(x-x^3y^2-1/2x^2y)
=3x^2y^2-3x^4y^4-3/2x^3y^3
=3(-1)^2-3*(-1)^4-(-1) ^3*3/2
=3/2

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