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幼苗
共回答了16个问题采纳率:81.3% 举报
1、(2x+y)??-(x+2y)??=[(2x+y)+(x+2y)][(2x+y)-(x+2y)]=(3x+3y)(x-y)=3(x+y)(x-y)2、4xy??-4x??y-y??=-y(4x??-4xy+y??)=-y(2x-y)??3、(a-b)(x-y)-(b-a)(x+y)=(a-b)(x-y)+(a-b)(x+y)=(a-b)[(x-y)+(x+y)]=2x(a-b)4、6xy??-9x??y-y??=-y(9x??-6xy+y??)=-y(3x-y)??
1年前
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