填空题:(a-b-c-d)(a+b-c+d)=[( )+( )][( )-( )]
问题描述:
填空题:(a-b-c-d)(a+b-c+d)=[( )+( )][( )-( )]
答
=[(a-b)- (c-d )][(a-b )+(c-d)]
填空题:(a-b-c-d)(a+b-c+d)=[( )+( )][( )-( )]
=[(a-b)- (c-d )][(a-b )+(c-d)]