A = 2018 . 20182017 - 2017 . 20182018 + 2019
= 2018 . 20182017 - 2017 . 10001 . 2018 + 2019
= 2018 . (20182017 - 20172017) + 2019
= 2018 . 10000 + 2019
= 20182019
Không bt có đúng ko nx
A=2018.20182017-2017.20182018+2019
A=2018.20182017-2017.2018.10001+2019
A=2018(20182017-20172017)+2019
A=2018.10000+2019
A=20180000+2019=20182019
chắc chắn đúng nhé :)