(a+b+c)(a+b- c)=[( )+( )][( )- ( )]
(a- b+c)(a+b- c)=[( )+( )][( )- ( )]
(a+b+c)(a- b- c)=[( )+( )][( )- ( )]
1.[ (a+b)+(C)][(a+b)-(c)]
2. [a+(b-c)][a-(b-c)]
3. [a+(b+c)][a-(b+c)]
2. [a+(b-c)][a-(b-c)]
3. [a+(b+c)][a-(b+c)]
温馨提示:答案为网友推荐,仅供参考
第1个回答 2012-03-18
(a+b+c)(a+b- c)=[(a+b)+(c)][(a+b)- (c)]
(a- b+c)(a+b- c)=[(a)+(b-c)][(a)- (b-c)]
(a+b+c)(a- b- c)=[(a)+(b+c)][(a)- (b+c)]
(a- b+c)(a+b- c)=[(a)+(b-c)][(a)- (b-c)]
(a+b+c)(a- b- c)=[(a)+(b+c)][(a)- (b+c)]