23.先化简再求值:3x2y-[2xy2-4(1/2xy-3/4x2y)+xy]+3xy2,其中x=3,y=-1

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23.先化简再求值:3x2y-[2xy2-4(1/2xy-3/4x2y)+xy]+3xy2,其中x=3,y=-1
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23.先化简再求值:3x2y-[2xy2-4(1/2xy-3/4x2y)+xy]+3xy2,其中x=3,y=-1
23.先化简再求值:3x2y-[2xy2-4(1/2xy-3/4x2y)+xy]+3xy2,其中x=3,y=-1

23.先化简再求值:3x2y-[2xy2-4(1/2xy-3/4x2y)+xy]+3xy2,其中x=3,y=-1
原式=6xy-4xy+2xy-6xy-xy+6xy=3xy
当x=3,y=-1时,原式=3*(-1)*3=-9

6XY-(4xy-2xy+3/2xy+xy)+6xy
12xy-9/2xy
15/2xy
15/2*3*(-1)
-45/2

原式=6xy-(4xy-2/xy+3/2xy+xy)+6xy=7xy-1/2xy;
将x=3,y=-1带入得:原式=-21+1/6=-125/6.
谢谢采纳!

化简:6xy-4xy+2xy-6xy-xy+6xy 合并同类项:3xy
将X=3 Y=-1代入 3乘以-3 等于-9 给我分吧