Ta có: 1+2-3-4+5+6-7-8+.....-2019-2020+2021+2022
=1+(2-3-4+5)+(6-7-8+9)+.....+(2018-2019-2020+2021)+2022
=1+0+0+.....+0+2022
=2023
Ta có: 1+2-3-4+5+6-7-8+.....-2019-2020+2021+2022
=1+(2-3-4+5)+(6-7-8+9)+.....+(2018-2019-2020+2021)+2022
=1+0+0+.....+0+2022
=2023
1+2-3-4+5-6-7-8+...-2019-2020+2021+2022
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
S = 1+2-3-4+5+6-7-8+9+10+ ..... + 2018-2019-2020+2021-2022+2023
2+3-4+5+6-7+8+9-10+...+2015+2016-2017+2018+2019-2020+2021+2022
Tính hợp lí (nếu có thể):
A= -1-2+3+4-5-6+7+8-9-10+...+2019+2020-2021-2022+2023
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
B = 1 - 2 - 3 + 4 - 5 - 6 +7-8- 9 +...+ 2020 - 2021 - 2022
1 - 2 + 3 - 4 + 5 - 6 + 7 - 8 + ..... + 2019 - 2020 + 2021