Tìm x: a) (x-1)^2=4 b) (x+2)^3=8

Tìm x:
a) (x-1)^2=4
b) (x+2)^3=8

0 thoughts on “Tìm x: a) (x-1)^2=4 b) (x+2)^3=8”

  1. `a) (x-1)^2=4`

    `⇔(x-1)^2=2^2`

        `(x-1)^2=-2^2`

    `⇔x-1=2`

        `x-1 =-2`

    `⇒x=3`

        `x=-1`

    Vậy `x∈{3;-1}`

    `b) (x+2)^3=8`

    `⇔(x+2)^3=2^3`

    `⇔x+2=2`

    `⇒x=0`

    Vậy `x=0`

    `#Stduy well`

    Reply
  2. Đáp án:

     

    Giải thích các bước giải:

    a) `(x-1)^2=4`

    `⇔ (x-1)^2=2^2`

    `⇔` \(\left[ \begin{array}{l}x-1=2\\x-1=-2\end{array} \right.\)

    `⇔` \(\left[ \begin{array}{l}x=3\\x=-1\end{array} \right.\)

    Vậy `x=-1,x=3`

    b) `(x+2)^3=8`

    `⇔ (x+2)^3=2^3`

    `⇔ x+2=2`

    `⇔ x=0`

    Vậy `x=0`

    Reply

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