TÍNH TỔNG S 22020. C20200 22018. C20202 22016. C20204 ... 2...
Câu 25: Tính tổng S 2
2020
. C
2020
0
2
2018
. C
2020
2
2
2016
. C
2020
4
... 2 .
0
C
2020
2020
.
3
2020
1
A. S 3
2020
1. B. S 3
2020
2020
2020
0
2018
2020
2
2016
2020
4
0
2020
2020
2020
2020
2020