已知 (x-y+2)的2次方+丨x-1丨=0 化简求值 -8xy-3(2-(xy+3)-2(3-2xy) )-21
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已知 (x-y+2)的2次方+丨x-1丨=0 化简求值 -8xy-3(2-(xy+3)-2(3-2xy) )-21
必须化简求值
必须化简求值
![已知 (x-y+2)的2次方+丨x-1丨=0 化简求值 -8xy-3(2-(xy+3)-2(3-2xy) )-21](/uploads/image/z/16367712-24-2.jpg?t=%E5%B7%B2%E7%9F%A5+%28x-y%2B2%EF%BC%89%E7%9A%842%E6%AC%A1%E6%96%B9%2B%E4%B8%A8x-1%E4%B8%A8%3D0+%E5%8C%96%E7%AE%80%E6%B1%82%E5%80%BC+-8xy-3%EF%BC%882-%EF%BC%88xy%2B3%29-2%283-2xy%29+%29-21)
解题思路: ∵(x-y+2)²≥0,(x-1)的绝对值≥0 又∵二者之和为0 ∴x-y+2=0,x-1=0 解得x=1,y=3 再将所求代数式化简,将x、y值代入
解题过程:
![](http://img.wesiedu.com/upload/5/20/520d89345b4a2b4fc11e44746ea68113.jpg)
解题过程:
![](http://img.wesiedu.com/upload/5/20/520d89345b4a2b4fc11e44746ea68113.jpg)
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