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

Toán Lớp 7: a) a) $\text{( 2x -1)}$$^{3}$ b) $\text{|x+ 1$\dfrac{1}{2}$|- $\dfrac{1}{2}$= 0}$ c) $\text{3| x| – 4$\dfrac{1}{2}$= 10 }$

Toán Lớp 7: a) a) $\text{( 2x -1)}$$^{3}$
b) $\text{|x+ 1$\dfrac{1}{2}$|- $\dfrac{1}{2}$= 0}$
c) $\text{3| x| – 4$\dfrac{1}{2}$= 10 }$

Comments ( 2 )

  1. a) (2x-1)^3=-125
    -> (2x-1)^3 = (-5)^3 = -125
    -> (2x-1)^3 = (-5)^3
    -> 2x-1=-5
            2x    =-5+1
            2x    =-4
               x    =-4:2
               x    =-2
    b) |x+1 1/2|-1/2=0
    |x+1 1/2|       =0+1/2
    |x+ 3/2|          =1/2
    => $\left[\begin{matrix} x+\dfrac{3}{2}=\dfrac{1}{2}\\ x+\dfrac{3}{2}=- \dfrac{1}{2}\end{matrix}\right.$
    => $\left[\begin{matrix} x=\dfrac{1}{2}-\dfrac{3}{2}\\ x=- \dfrac{1}{2}-\dfrac{3}{2}\end{matrix}\right.$
    => $\left[\begin{matrix} x=-1\\ x=- 2\end{matrix}\right.$
      Vậy x=-1 hoặc x=-2
    c) 3|x|-4 1/2=10
    3|x|-9/2=10
    3|x|       =10+9/2
    3|x|       =29/2
        |x|      =29/2:3
        |x|      =29/6
    => $\left[\begin{matrix} x=\dfrac{29}{6}\\ x=-\dfrac{29}{6}\end{matrix}\right.$
     Vậy x=29/6 hoặc x=-29/6

  2. Giải đáp + Lời giải và giải thích chi tiết

    toan-lop-7-a-a-tet-2-1-3-b-tet-1-dfrac-1-2-dfrac-1-2-0-c-tet-3-4-dfrac-1-2-10

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