![](https://iknow-base.cdn.bcebos.com/lxb/notice.png)
先化简,再求值3x²y-[2xy²-2(xy-3/2x²y)+2xy]-2x²y
先化简,再求值:3x²y-[2xy²-2(xy-3/2x²y)+2xy]-2x²y,其中x,y满足(x+2)²+丨y-1...
先化简,再求值:3x²y-[2xy²-2(xy-3/2x²y)+2xy]-2x²y,其中x,y满足(x+2)²+丨y-1丨=0
展开
1个回答
2014-11-15
展开全部
x,y满足(x+2)²+丨y-1丨=0,则x+2=0,x=-2;y-1=0,y=1
3x²y-[2xy²-2(xy-3/2x²y)+2xy]-2x²y=3x²y-(2xy²-2xy+3x²y+2xy)-2x²y
=3x²y-2xy²-3x²y-2x²y=-2xy²-2x²y=-2xy(y-x)
将x=-2,y=1代入得-2xy(y-x)=-2X(-2)(1+2)=12
3x²y-[2xy²-2(xy-3/2x²y)+2xy]-2x²y=3x²y-(2xy²-2xy+3x²y+2xy)-2x²y
=3x²y-2xy²-3x²y-2x²y=-2xy²-2x²y=-2xy(y-x)
将x=-2,y=1代入得-2xy(y-x)=-2X(-2)(1+2)=12
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询