A=20222−20212+20202−20192+...+22−1�=20222-20212+20202-20192+...+22-1
=(2022−2021)(2022+2021)+(2020−2019)(2020+2019)+....+(2−1)(2+1)=(2022-2021)(2022+2021)+(2020-2019)(2020+2019)+....+(2-1)(2+1)
=1.4043+1.4039+.....+1.3=1.4043+1.4039+.....+1.3
Vì từ 3→40433→4043 có 10111011 số
⇒A=(4043+3).10112⇒�=(4043+3).10112
=4046.10112=2023.1011=4046.10112=2023.1011
=2045253