如题所述
第1个回答 2015-04-02
789×1001
=789×(1000+1)
=789×1000+789×1
=789000+789
=789789本回答被提问者和网友采纳
=789×(1000+1)
=789×1000+789×1
=789000+789
=789789本回答被提问者和网友采纳
第2个回答 2015-04-02
789X1001=
(790-1)X1001=790X1001-1X1001=790X(1000+1)-1X1001=790000+790-1001=790790-1000-1
=789790-1=789789
(790-1)X1001=790X1001-1X1001=790X(1000+1)-1X1001=790000+790-1001=790790-1000-1
=789790-1=789789
