Lời giải:
$A=(-1-2+3+4)+(-5-6+7+8)+(-9-10+11+12)+...+(-2021-2022+2023+2024)-2024$
$=\underbrace{4+4+...+4}_{506}-2024$
$=4.506-2024=0$
S = 1+2-3-4+5+6-7-8+9+10+ ..... + 2018-2019-2020+2021-2022+2023
1-2-3+4+5-6-7+8+...+2018-2019-2020+2021+2022-2023
tính :
A= 1+2-3-4+5+6-7-8+9+...+2018-2019-2020+2021-2022
2+3-4+5+6-7+8+9-10+...+2015+2016-2017+2018+2019-2020+2021+2022
Bài 1: Tính nhanh
A = 1 - 3 + 5 - 7+...- 2019 + 2021 - 2023
B = 1 + 2 - 3 - 4 + 5 + 6 - 7 - 8 + 9 +...+ 2017 + 2018 + - 2019 - 2020
Help me :v
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=\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}\)
1+2-3-4+5-6-7-8+...-2019-2020+2021+2022
1+2-3-4+5+6-7-8-....-2019-2020+2021+2022 help
1) Tính hợp lý :
P=1-2-3+4+5-6-7+8+.........+2021-2022-2023+2024
