先化简再求值:2(x²y+xy)-3(x²y-xy)-4x²y 其中x=-1,y=1先化简再求值:2(x²y+xy)-3(x²y-xy)-4x²y 其中x=-1,y=1

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先化简再求值:2(x²y+xy)-3(x²y-xy)-4x²y 其中x=-1,y=1先化简再求值:2(x²y+xy)-3(x²y-xy)-4x²y 其中x=-1,y=1

先化简再求值:2(x²y+xy)-3(x²y-xy)-4x²y 其中x=-1,y=1先化简再求值:2(x²y+xy)-3(x²y-xy)-4x²y 其中x=-1,y=1
先化简再求值:2(x²y+xy)-3(x²y-xy)-4x²y 其中x=-1,y=1
先化简再求值:
2(x²y+xy)-3(x²y-xy)-4x²y
其中x=-1,y=1

先化简再求值:2(x²y+xy)-3(x²y-xy)-4x²y 其中x=-1,y=1先化简再求值:2(x²y+xy)-3(x²y-xy)-4x²y 其中x=-1,y=1
=-5x^2*y+5xy
=5xy(1-x)=-10

2(x²y+xy)-3(x²y-xy)-4x²y
=2x²y+2xy-3x²y+3xy-4x²y
=-5x²y+5xy
=-5xy(x-1)
=-5*(-1)*1*(-1-1)
=5*(-2)
=-10

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