Register Now

Login

Lost Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

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

Toán Lớp 8: tìm x, biết: (3x – 1)^2 = (x – 1)^2

Home/ Toán Lớp 8: tìm x, biết: (3x – 1)^2 = (x – 1)^2

Toán Lớp 8: tìm x, biết: (3x – 1)^2 = (x – 1)^2

Tháng Tư 17, 2022 Toán học 2 Comments 0 views

Toán Lớp 8: tìm x, biết: (3x – 1)^2 = (x – 1)^2

Comments ( 2 )

  1. hatuanlan
    hatuanlan
    17 Tháng Tư, 2022 at 1:28 sáng
    Reply
    Answer
    (3x – 1)^2 = (x – 1)^2
    => (3x – 1)^2 – (x – 1)^2 = 0
    => 9x^2 – 6x + 1 – x^2 + 2x – 1 = 0
    => (9x^2 – x^2) + (2x – 6x) + (1 – 1) = 0
    => 8x^2 – 4x = 0
    => 4x . (2x – 1) = 0
    TH1: 4x = 0
    => x = 0 : 4
    => x = 0
    TH2: 2x – 1 = 0
    => 2x = 1
    => x = 1 : 2
    => x = 1/2
    Vậy x \in {0 ; 1/2}

  2. myngocla
    myngocla
    17 Tháng Tư, 2022 at 1:27 sáng
    Reply
    $(3x-1)^2=(x-1)^2\\\to (3x-1)^2-(x-1)^2=0\\\to (3x-1-x+1)(3x-1+x-1)=0\\\to 2x (4x-2)=0\\\to \left[ \begin{array}{l}2x=0\\4x-2=0\end{array} \right.\\\to \left[ \begin{array}{l}x=0\\x=\dfrac{1}{2}\end{array} \right.$
    Vậy $x=0$ hoặc $x=\dfrac{1}{2}$
     

Leave a reply

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

Kiều Nguyệt

About Kiều Nguyệt