Answer:
Step-by-step explanation:
Remark
The numbers here when subtracted, make 1.
ie 2021 - 2020 = 1
So all you have is 2020+2021 = 4041
(2021 - 2020)(2021 + 2020) = 4041
This doesn't work for every number you could choose, but it works for these 2.