mọi người lm nhanh nha

$\text{Đáp án + Giải thích các bước giải:}$

$\text{Ta có :}$   

`B` `=` `1-1/2+1/3-1/4+...+1/2021-1/2022+1/2023`

`=>` `B` `=` `(1+1/3+1/5+...+1/2021+1/2023)` `-` `(1/2+1/4+1/6+...+1/2020+1/2022)`

`<=>` `B` `=` `(1+1/2+1/3+1/4+1/5+...+1/2021+1/2022+1/2023)` `-` `2(1/2+1/4+1/6+...+1/2020+1/2022)`

`=>` `B` `=` `(1+1/2+1/3+1/4+1/5+...+1/2021+1/2022+1/2023)` `-` `(1+1/2+1/3+1/4+1/5+...+1/1011)`

`=>` `B` `=` `1/1012+1/1013+1/1014+...+1/2022+1/2023` 

`=>` `B` `-` `C` `=` `(1/1012+1/1013+1/1014+...+1/2022+1/2023)` `-` `(1/1012+1/1013+1/1014+...+1/2022+1/2023)` 

`=>` `B` `-` `C` `=` `0`