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

Question

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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Delwyn 4 years 2020-10-14T03:41:40+00:00 1 Answers 124 views 0

Answers ( )

  1. minhkhoi
    0
    2020-10-14T03:43:25+00:00
    Reply

     $a)x^2-2x+1=0$

    $⇔(x-1)^2=0$

    $⇔x-1=0$

    $⇔x=1$

    $\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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Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )