如题所述
第1个回答 2017-03-23
78x101-58=(78x100+78)-58=78x100+20=7820
第2个回答 2017-03-23
78x101-58
=78x100+78x1-58
=7800+(78-58)
=7800+20
=7820本回答被网友采纳
=78x100+78x1-58
=7800+(78-58)
=7800+20
=7820本回答被网友采纳
第3个回答 2017-03-23
78x101-58
=78x100+78x1-58
=7800+78-58
=7800+20
=7820
=78x100+78x1-58
=7800+78-58
=7800+20
=7820
第4个回答 2017-03-23
78×101-58
=78×101-78+20
=78×100+20
=7800+20
=7820
=78×101-78+20
=78×100+20
=7800+20
=7820
