\(S=1+2-3-4+5+6-7-8+9+10-...+2018-2019-2020+2021\)
\(S=0+1-1+1-1+...-1-+1=0\)
\(S=1+2-3-4+5+6-7-8+9+10-...+2018-2019-2020+2021\)
\(S=0+1-1+1-1+...-1-+1=0\)
Tính S= 1 + 2 - 3 - 4 + 5 + 6 - 7 - 8 + 9 + 10 - ... + 2018 - 2019 - 2020 + 2021
Tính S= 1+2-3-4+5+6-7-8+9+10- .......+2018-2019-2020+2021
Tính: S = 1+2-3-4+5+6-7-8+9+10+ ..... + 2018-2019-2020+2021
tính s = 1 + 2 - 3 - 4 + 5 + 6 - 7 - 8 + 9 + 10 -... + 2018 - 2019 - 2020 + 2021
S = 1+2-3-4+5+6-7-8+9+10+ ..... + 2018-2019-2020+2021-2022+2023
Câu 30. Giá trị của tổng
S =1+ 2 - 3 - 4 + 5 + 6 - 7 - 8 + 9 +10 -... + 2018 - 2019 - 2020 + 2021 là
A. 2020 . B. 2021. C. 1. D. -1.
Tính hợp lý:
a) A=\(2021^2\)-2020.(2021+1)
b) B=1+2-3-4+5+6-7-8+9+10-...+2018-2019-2020+2021
c) C=\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}\)
B= 1+2-3-4+5+6-7-8+9+10-...+2018-2019-2020+2021
1+2-3-4+5+6-7-8+9+10-11-12...+2018-2019-2020+2021