Cho mình xin 1 slot thôi nhé! Tìm `x` biết `x/1.2+x/2.3+x/3.4+…+x/2020.2021=x`.

Đáp án:

`x=0` 

Giải thích các bước giải:

`x/1.2+x/2.3+x/3.4+…+x/2020.2021=x`
`=>x.(1/1.2+1/2.3+1/3.4+…+1/2020.2021)=x`
`=>x.(1/1-1/2+1/2-1/3+1/3-1/4+…+1/2020-1/2021)=x`
`=>x.(1/1-1/2021)=x`
`=>x.(2021/2021-1/2021)=x`
`=>x. 2020/2021=x`
`=>x. 2020/2021 – x=0`
`=>x.(2020/2021-1)=0`
`=>x . (2020/2021-2021/2021)=0`
`=>x.(-1)/2021=0`
`=>x=0:(-1)/2021`
`=>x=0`
Vậy `x=0`