2xy-1/2(4xy-8x²y²)+2(3xy-5x²y²),其中x=3/2,y=-2/3

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2xy-1/2(4xy-8x²y²)+2(3xy-5x²y²),其中x=3/2,y=-2/3

x=3/2,y=-2/3
xy=3/2*(-2/3)=-1
2xy-1/2(4xy-8x²y²)+2(3xy-5x²y²)
=2xy-2xy+4x²y²+6xy-10x²y²
=(2-2+6)xy+(4-10)x²y²
=6xy-6x²y²
=6xy(1-xy)
=-1*[1-(-1)]
=1*2
=2