2018x2020-2017x2021如何巧算?

2024-10-31 19:30:23
有2个网友回答
网友(1):

解:原式=(2017+1)*2020-2017*(2020+1)
=2017*2020+2020-2017*2020-2017
=2020-2017=3

网友(2):

2018x2020-2017x2021
=2017x2020+2020-2017x2020-2017
=2017x2020-2017x2020+2020-2017
=2020-2017
=3