x ²-2x+4=(2x-2) ² tinh giup minh vs nha mng 09/07/2021 Bởi Quinn x ²-2x+4=(2x-2) ² tinh giup minh vs nha mng
`x^2-2x+4=(2x-2)^2` `⇔x^2-2x+4=(2x)^2-2.2x.2+2^2` `⇔x^2-2x+4=4x^2-8x+4` `⇔x^2-4x^2-2x+8x=4-4` `⇔-3x^2+6x=0` `⇔-3x(x-2)=0` `⇔`\(\left[ \begin{array}{l}`3x=0\\x-2=0\end{array} \right.\) `⇔`\(\left[ \begin{array}{l}`x=0\\x=2\end{array} \right.\) $\text{Vậy S={0;2}.}$ Bình luận
$x^{2}-2x+4=(2x-2)^{2}$ ⇔$x^{2}-2x+4=4x^{2}-8x+4$ ⇔$x^{2}-2x-4x^{2}+8x=4-4$ ⇔$-3x^{2}+6x=0$ ⇔$-3x(x-2)=0$ ⇔\(\left[ \begin{array}{l}-3x=0\\x-2=0\end{array} \right.\) ⇔\(\left[ \begin{array}{l}x=0\\x=2\end{array} \right.\) Vậy $x=0$ hoặc $x=2$ Bình luận
`x^2-2x+4=(2x-2)^2`
`⇔x^2-2x+4=(2x)^2-2.2x.2+2^2`
`⇔x^2-2x+4=4x^2-8x+4`
`⇔x^2-4x^2-2x+8x=4-4`
`⇔-3x^2+6x=0`
`⇔-3x(x-2)=0`
`⇔`\(\left[ \begin{array}{l}`3x=0\\x-2=0\end{array} \right.\)
`⇔`\(\left[ \begin{array}{l}`x=0\\x=2\end{array} \right.\)
$\text{Vậy S={0;2}.}$
$x^{2}-2x+4=(2x-2)^{2}$
⇔$x^{2}-2x+4=4x^{2}-8x+4$
⇔$x^{2}-2x-4x^{2}+8x=4-4$
⇔$-3x^{2}+6x=0$
⇔$-3x(x-2)=0$
⇔\(\left[ \begin{array}{l}-3x=0\\x-2=0\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=0\\x=2\end{array} \right.\)
Vậy $x=0$ hoặc $x=2$