Toán CMR: $x^{3k}\vdots x^3-1 ⇒x^{3k}\vdots x^2+x+1$ 21/07/2021 By Quinn CMR: $x^{3k}\vdots x^3-1 ⇒x^{3k}\vdots x^2+x+1$
Ta có: $x^{3k} \,\,\vdots\,\,x^3 -1$ $\Leftrightarrow x^{3k} \,\,\vdots\,\,(x-1)(x^2 + x + 1)$ $\Rightarrow x^{3k} \,\,\vdots\,\,x^2 + x + 1$ Trả lời
`x^(3k) \vdots x^3-1`
`⇒x^(3k) \vdots (x^2+x+1)(x-1)`
`⇒x^(3k) \vdots x^2+x+1`
Ta có: $x^{3k} \,\,\vdots\,\,x^3 -1$
$\Leftrightarrow x^{3k} \,\,\vdots\,\,(x-1)(x^2 + x + 1)$
$\Rightarrow x^{3k} \,\,\vdots\,\,x^2 + x + 1$