1 Tìm x bt a x^2-2x+1=0 b 9-6x+x^2=0 c 25x^2-10x+1=10 d 49x^2-28x+4

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1.  $a)x^2-2x+1=0$

   $⇔(x-1)^2=0$

   $⇔x-1=0$

   $⇔x=1$

   $\text{Vậy $x=1$}$

   $b)9-6x+x^2=0$

   $⇔(3-x)^2=0$

   $⇔3-x=0$

   $⇔x=3$

   $\text{Vậy $x=3$}$

   $c)25x^2-10x+1=0$

   $⇔(5x-1)^2=0$

   $⇔5x-1=0$

   $⇔5x=1$

   $⇔x=\dfrac{1}{5}$

   $\text{Vậy $x=\dfrac{1}{5}$}$

   $d)49x^2-28x+4=0$

   $⇔(7x-2)^2=0$

   $⇔7x-2=0$

   $⇔7x=2$

   $⇔x=\dfrac{2}{7}$

   $\text{Vậy $x=\dfrac{2}{7}$}$

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