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

Toán Lớp 8: Tìm x biết: (x ³ – x ²) – 4x ² + 8x – 4 = 0 nhanh nha mn please

Home/ Toán Lớp 8: Tìm x biết: (x ³ – x ²) – 4x ² + 8x – 4 = 0 nhanh nha mn please

Toán Lớp 8: Tìm x biết: (x ³ – x ²) – 4x ² + 8x – 4 = 0 nhanh nha mn please

Tháng Sáu 2, 2022 Toán học 2 Comments 0 views

Toán Lớp 8: Tìm x biết:
(x ³ – x ²) – 4x ² + 8x – 4 = 0
nhanh nha mn please

Comments ( 2 )

  1. landinhngoc97
    landinhngoc97
    2 Tháng Sáu, 2022 at 10:55 chiều
    Reply
    ( x^3 – x^2 ) – 4x^2 + 8x – 4 = 0
    ⇔x^3 – x^2 – 4x^2 + 4x + 4x – 4 = 0
    ⇔ x^2 . ( x – 1 ) – 4x . ( x – 1 ) + 4 . ( x – 1 ) = 0
    ⇔ ( x – 1 ) . ( x^2 – 4x + 4 ) = 0
    ⇔ ( x – 1 ) . ( x – 2 )^2 = 0
    ⇔ \(\left[ \begin{array}{l}x – 1 = 0\\( x – 2 )^2 = 0\end{array} \right.\) 
    ⇔ \(\left[ \begin{array}{l}x = 1\\x – 2 = 0\end{array} \right.\) 
    ⇔ \(\left[ \begin{array}{l}x = 1\\x = 2\end{array} \right.\) 
    Vậy , x ∈ { 1 ; 2 }

  2. maitrucloan
    maitrucloan
    2 Tháng Sáu, 2022 at 10:55 chiều
    Reply
    $\#phnn$
    (x^3-x^2)-4x^2+8x-4=0
    <=>x^2(x-1)-[(2x)^2-2.2x.2+2^2]=0
    <=>x^2(x-1)-(2x-2)^2=0
    <=>x^2(x-1)-(2x-2)(2x-2)=0
    <=>x^2(x-1)-[2(x-1).2.(x-1)]=0
    <=>x^2(x-1)-4(x-1)^2=0
    <=>(x-1)[x^2-4(x-1)]=0
    <=>(x-1)(x^2-4x-4)=0
    <=>(x-1)[-(x^2+4x+4)]=0
    <=>(x-1)[-(x^2+2.x.2+2^2)]=0
    <=>-(x-1)(x+2)^2=0
    <=>(x-1)(x+2)^2=0
    =>x-1=0 \text{(Vì} (x+2)^2>0∀x)
    <=>x=1.

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

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