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(2m-n)²-(3m+2)²

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/10/06 13:11:21
(2m-n)²-(3m+2)²
(7a-8b)²-4x²
(x²+xy+y²)(x²-xy+y²)-(x²+y²)²
1、2是因式分解
(2m-n)²-(3m+2)²
=(2m-n+3m+2)(2m-n-3m-2)
=(5m-n+2)(-m-n-2)
=-(5m-n+2)(m+n+2)
(7a-8b)²-4x²
=(7a-8b+2x)(7a-8b-2x)
(x²+xy+y²)(x²-xy+y²)-(x²+y²)²
=(x²+y²)²-(xy)²-(x²+y²)²
=-x²y²