2021✖️20202019一2019✖️20202021巧算怎么算?
发布网友
发布时间：2022-07-31 02:04
共1个回答
热心网友
时间：2024-11-25 13:33
*2021x20202019一2019x20202021
=2021x(20202020-1) - 2019x(20202020+1)
=2021x20202020-2021-2019x20202020-2019
=2x20202020-4040
=40404040-4040
=40400000
或
*2021x20202019一2019x20202021
=(2020+1)x20202019 - (2020-1)x20202021
=2020x20202019+20202019-2020x20202021+20202021
=(2020x20202019-2020x20202021) + 40404040
【前两项提取2020】
=2020x(20202019-20202021)
=-2020x2+ 40404040
=-4040+40404040
=40400000
