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222-9+11+12:2*14+14 = ? ( )

Toán Lớp 7: Tìm `x` `b) |x|= 0` `c) |x+1|= 2/3` Giúp iem

Toán Lớp 7: Tìm x
b) |x|= 0
c) |x+1|= 2/3
Giúp iem

Comments ( 2 )

  1. $\text{ b) | x | = 0 }$
    $\Rightarrow$ $\text{ x = 0 }$
    $\text{ Vậy x = 0 }$
    $\text{ c) | x + 1 | = $\dfrac{2}{3}$ }$
    $\Rightarrow$ $\begin{cases} x + 1 = \dfrac{2}{3}\\x + 1 = \dfrac{-2}{3}\end{cases}$
    $\Rightarrow$ $\begin{cases} x = \dfrac{2}{3} – 1\\x = \dfrac{-2}{3} – 1\end{cases}$
    $\Rightarrow$ $\begin{cases} x = \dfrac{-1}{3}\\x = \dfrac{-5}{3}\end{cases}$
      $Vậy$ $x$ $∈$ { $\dfrac{-1}{3}$ ; $\dfrac{-5}{3}$ }

  2. b) |x| = 0 ⇒ x = 0
    c) |x+1| = 2/3
    TH1: x≥-1
    ⇒ x+1 = 2/3
    ⇔ x = -1/3
    TH2: x<-1
    ⇒ x+1 = -2/3
    ⇔ x = -5/3
    Vậy, x ∈ {-1/3; -5/3}

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222-9+11+12:2*14+14 = ? ( )

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