题目内容
下列式子中正确的是
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A.(-x+3y)-(2x-5y)=-x-2y
B.1-2(x2-x+1)=-2x2+2x-1
C.(2x+y-z)-(5x+y-z)=-2x-4y-2z
D.2(x2-2xy+y2)-(x2-4xy+2y2)=x2+4y2
B.1-2(x2-x+1)=-2x2+2x-1
C.(2x+y-z)-(5x+y-z)=-2x-4y-2z
D.2(x2-2xy+y2)-(x2-4xy+2y2)=x2+4y2
B
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