Giải pt: `(x+1)/(x^2+x+1)+(x-1)/(x^2-x+1)=3/(x^5+x^3+x)` 18/07/2021 Bởi Vivian Giải pt: `(x+1)/(x^2+x+1)+(x-1)/(x^2-x+1)=3/(x^5+x^3+x)`
`(x+1)/(x^2+x+1)+(x-1)/(x^2-x+1)=(3)/(x^5+x^3+x)` `⇔((x+1)(x^2-x+1)+(x-1)(x^2+x+1))/(x^4+x^2+1)=3/(x(x^4+x^2+1))` `⇔(x+1)(x^2-x+1)+(x-1)(x^2+x+1)=3/x` `⇔2=3/x` `⇔x=3/2` Bình luận
Đáp án:
Đây nek
`(x+1)/(x^2+x+1)+(x-1)/(x^2-x+1)=(3)/(x^5+x^3+x)`
`⇔((x+1)(x^2-x+1)+(x-1)(x^2+x+1))/(x^4+x^2+1)=3/(x(x^4+x^2+1))`
`⇔(x+1)(x^2-x+1)+(x-1)(x^2+x+1)=3/x`
`⇔2=3/x`
`⇔x=3/2`