(3x^2y-2xy^2)-2(x^2y-2xy^2)其中x=-4,y=-1/2化简求值

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(3x^2y-2xy^2)-2(x^2y-2xy^2)其中x=-4,y=-1/2化简求值

(3x^2y-2xy^2)-2(x^2y-2xy^2)其中x=-4,y=-1/2化简求值
(3x^2y-2xy^2)-2(x^2y-2xy^2)其中x=-4,y=-1/2化简求值

(3x^2y-2xy^2)-2(x^2y-2xy^2)其中x=-4,y=-1/2化简求值
(3x^2y-2xy^2)-2(x^2y-2xy^2)
=x^2y+2xy^2
=xy(x+2y)
=-4x-1/2x(-4-1/2x2)
=2x-5
=-10

=(3-2)x^2y+(-2+4)xy^2=x^2y+2xy^2=xy(x+2y)=2*(-5)=-10

(3x^2y-2xy^2)-2(x^2y-2xy^2)=(3-2)x^2y+(-2+4)xy^2=x^2y+2xy^2=xy(x+2y)=2*(-5)
带入数字 得到-10