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

Toán Lớp 7: Helpppppppppppp (2x+1mũ)2 – = |-14|

Home/ Toán Lớp 7: Helpppppppppppp (2x+1mũ)2 – = |-14|

Toán Lớp 7: Helpppppppppppp (2x+1mũ)2 – = |-14|

Tháng Tám 14, 2022 Toán học 2 Comments 0 views

Toán Lớp 7: Helpppppppppppp
(2x+1mũ)2 – = |-14|

Comments ( 2 )

  1. thanhmaianh
    thanhmaianh
    14 Tháng Tám, 2022 at 1:52 sáng
    Reply
    $(2x + 1)^{2}$ -2 = |-14|
    $(2x + 1)^{2}$  = 14 + 2
    $(2x + 1)^{2}$  = 16
    $(2x + 1)^{2}$ = $4^{2}$
    -> 2x + 1 = 4
    \(\left[ \begin{array}{l}2x + 1 = 4\\2x + 1 = -4\end{array} \right.\)
    TH1 : 2x + 1 = 4
                2x    = 4 – 1
                 2x   = 3
                  x    = 3 : 2
                  x     = 1,5
    TH2 : 2x + 1 = – 4
                     2x= -4 – 1
                    2x = – 5
                      x = – 5 : 2
                      x = – 2,5
    Vậy x ∈ { 1,5; -2,5 }

  2. catlantuong
    catlantuong
    14 Tháng Tám, 2022 at 1:52 sáng
    Reply
    (2x + 1)^{2} – 2 = |-14|
    $\Leftrightarrow$ (2x + 1)^{2} – 2 = 14
    $\Leftrightarrow$ (2x + 1)^{2} = 14 + 2
    $\Leftrightarrow$ (2x + 1)^{2} = 16
    $\Leftrightarrow$ (2x + 1)^{2} = (+- 4)^{2}
    $\Leftrightarrow$ 2x + 1 = +- 4
    $\Leftrightarrow$ $\left[\begin{matrix} 2x+1=4\\ 2x+1=-4\end{matrix}\right.$
    $\Leftrightarrow$ $\left[\begin{matrix} 2x=4-1\\ 2x=-4-1\end{matrix}\right.$
    $\Leftrightarrow$ $\left[\begin{matrix} 2x=3\\ 2x=-5\end{matrix}\right.$
    $\Leftrightarrow$ $\left[\begin{matrix} x=3:2\\ x=-5:2\end{matrix}\right.$
    $\Leftrightarrow$ $\left[\begin{matrix} x=\dfrac{3}{2}\\ x=\dfrac{-5}{2}\end{matrix}\right.$
    $\text{Vậy}$ x \in {3/2 ; {-5}/2}
     

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

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