99×43加98×42加97×41简便算法
第1个回答 2016-07-18
99x43+98x42+97x41
=(100-1)x43+(100-2)x42+(100-3)x41
=(100x43-1x43)+(100x42-2x42)+(100x41-3x41)
=(4300-43)+(4200-74)+(4100-123)
=4257+4116+3977
=8373+3977
=12350
=(100-1)x43+(100-2)x42+(100-3)x41
=(100x43-1x43)+(100x42-2x42)+(100x41-3x41)
=(4300-43)+(4200-74)+(4100-123)
=4257+4116+3977
=8373+3977
=12350
第2个回答 推荐于2017-09-21
99×43+98×42+97×41
=(98+1)×43+98×42+(98-1)×41
=98×(43+42+41)+(43-41)
=98×126+2
=(100-2)×126+2
=12600-252+2
=12600-250
=12350本回答被网友采纳
=(98+1)×43+98×42+(98-1)×41
=98×(43+42+41)+(43-41)
=98×126+2
=(100-2)×126+2
=12600-252+2
=12600-250
=12350本回答被网友采纳
第3个回答 2016-07-18
追答
第4个回答 2016-07-18
(100-1)x(40+3)+(100-2)x(40+2)+(100-3)x(40+1)=100x40x3+(3+2+1)x100-(1+2+3)x40-3-4-3=12000+600-240-10=12350
第5个回答 2016-07-18
(100-1)×43+(100-2)×42+(100-3)×41