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

Toán Lớp 8: 3x^3-7x^2+6x=14. Giúp mình vs ạ

Toán Lớp 8: 3x^3-7x^2+6x=14.
Giúp mình vs ạ

Comments ( 2 )

  1. 3x^3 – 7x^2 + 6x = 14
    => 3x^3 – 7x^2 + 6x – 14 = 0
    => ( 3x^3 + 6x ) – ( 7x^2 + 14 ) = 0
    => 3x ( x^2 + 2 ) – 7 ( x^2 + 2 ) = 0
    => ( x^2 + 2 ) ( 3x – 7 ) = 0
    => \(\left[ \begin{array}{l}x^2+2=0\\3x-7=0\end{array} \right.\) 
    => \(\left[ \begin{array}{l}x^2=-2 ( loại ) \\3x=7\end{array} \right.\) 
    => 3x = 7
    => x = 7/3  
    Vậy x = 7/3  

  2. Bạn tham khảo !
    3x^3-7x^2+6x=14
    <=>(3x^3-7x^2)+6x-14=0
    <=>x^2(3x-7)+2.(3x-7)=0
    <=>(x^2+2)(3x-7)=0
    <=>[(x^2=-2(x^2>=0)),(3x=7):}
    <=>x=7/3
    Vậy x=7/3
    _________________________________________
    3x^3-7x^2+6x=14
    <=>3x^3+6x-7x^2-14=0
    <=>3x(x^2+2)-7(x^2+2)=0
    <=>(3x-7)(x^2+2)=0
    <=>[(x^2=-2(x^2>=0)),(3x=7):}
    <=>x=7/3
    Vậy x=7/3

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