如题所述
第1个回答 2021-02-04
第2个回答 2021-02-04
818181x42-81x424242
=10101x81x42-81x42x10101
=0
=10101x81x42-81x42x10101
=0
第3个回答 2021-02-04
818181×42-81×424242
=81×10101×42-81×10101×42
=0
=81×10101×42-81×10101×42
=0
第4个回答 2021-02-05
简便计算如下
818181×42-81×424242
=81×10101×42-81×424242
=81×(10101×42-424242)
=81×(424242-424242)
=81×0
=0
818181×42-81×424242
=81×10101×42-81×424242
=81×(10101×42-424242)
=81×(424242-424242)
=81×0
=0
第5个回答 2021-02-04
这道题看着数字很大,但观察发现818181和424242有同样的规矩,分解开就好算了。解答如下:
818181×42-81×424242
=81×10101×42-81×42×10101
=81×10101×(42-42)
=0
818181×42-81×424242
=81×10101×42-81×42×10101
=81×10101×(42-42)
=0