x + 721/2020 + x + 21/700 + x + 721/2021 = -1 11/08/2021 Bởi Savannah x + 721/2020 + x + 21/700 + x + 721/2021 = -1
Tham khảo `\frac{x+721}{2020}+\frac{x+21}{700}+\frac{x+721}{2021}=-1` `⇒ \frac{x+721}{2020}+\frac{x+21}{700}+1+\frac{x+721}{2021}=-1+1` `⇒\frac{x+721}{2020}+\frac{x+721}{700}+\frac{x+721}{2021}=0` `⇒(x+721)(\frac{1}{2020}+\frac{1}{700}+\frac{1}{2021})=0` `⇔x+721=0`(Do ` \frac{1}{2020}+\frac{1}{700}+\frac{1}{2021} \ne 0)` `⇒x=-721` `\text{©CBT}` Bình luận
Đáp án $ x= -721$ Giải thích các bước giải: `(x + 721)/2020 + (x + 21)/700 + (x + 721)/2021 = -1` `=>(x + 721)/2020 + (x + 21)/700 + (x + 721)/2021+1 = (-1)+1` `=>(x+721)/2020+(x+21)/700+(x+721)/2021+700/700=0` `=>(x+721)/2020+((x+21)/700+700/700)+(x+721)/2021=0` `=>(x+721)/2020+(x+721)/700+(x+721)/2021=0` `=>(x+721).(1/2020+1/700+1/2021)=0` `=>x+721=0` `=>x=0-721` `=>x=-721` Vậy `x=-721` Bình luận
Tham khảo
`\frac{x+721}{2020}+\frac{x+21}{700}+\frac{x+721}{2021}=-1`
`⇒ \frac{x+721}{2020}+\frac{x+21}{700}+1+\frac{x+721}{2021}=-1+1`
`⇒\frac{x+721}{2020}+\frac{x+721}{700}+\frac{x+721}{2021}=0`
`⇒(x+721)(\frac{1}{2020}+\frac{1}{700}+\frac{1}{2021})=0`
`⇔x+721=0`(Do ` \frac{1}{2020}+\frac{1}{700}+\frac{1}{2021} \ne 0)`
`⇒x=-721`
`\text{©CBT}`
Đáp án
$ x= -721$
Giải thích các bước giải:
`(x + 721)/2020 + (x + 21)/700 + (x + 721)/2021 = -1`
`=>(x + 721)/2020 + (x + 21)/700 + (x + 721)/2021+1 = (-1)+1`
`=>(x+721)/2020+(x+21)/700+(x+721)/2021+700/700=0`
`=>(x+721)/2020+((x+21)/700+700/700)+(x+721)/2021=0`
`=>(x+721)/2020+(x+721)/700+(x+721)/2021=0`
`=>(x+721).(1/2020+1/700+1/2021)=0`
`=>x+721=0`
`=>x=0-721`
`=>x=-721`
Vậy `x=-721`