解:原式=-4xy²+12x²y-4-12x²y-6xy²+3x
=-10xy²+3x-4
∴当x=-2,y=1时,原式=-10×(-2)×1²+3×(-2)-4=10
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4(-xy²+3x²y-1)-3(4x²y+2xy²-x)=-4xy^2+12x^2y-4-12x^2y-6xy^2+3x=-10xy^2-4+3x=20-4-6=10
4(-xy²+3x²y-1)-3(4x²y+2xy²-x)
=-4xy²-6xy²-4+3x
=-10xy²+3x-4
=20-6-4
=10
这是神马题目。一堆乱码的说