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: `x^2-2x-8=0` Helpaaaaaaaaaaaaaaaaaaaaaaa

Toán Lớp 8: x^2-2x-8=0
Helpaaaaaaaaaaaaaaaaaaaaaaa

Comments ( 2 )

  1. $x^2-2x-8=0$
    $⇔x^2+2x-4x-8=0$
    $⇔x(x+2)-4(x+2)=0$
    $⇔(x+2)(x-4)=0$
    $+,x+2=0$
    $⇔x=-2$
    $+,x-4=0$
    $⇔x=4$
    Vậy S={-2;4}
     

  2. Giải đáp+Lời giải và giải thích chi tiết: 
        x^2-2x-8=0
    <=> (x^2-4x)+(2x-8)=0
    <=> x(x-4)+2(x-4)=0
    <=> (x-4)(x+2)=0
    <=> \(\left[ \begin{array}{l}x-4=0\\x+2=0\end{array} \right.\) 
    <=> \(\left[ \begin{array}{l}x=4\\x=-2\end{array} \right.\) 
    Vậy S={4;-2}

Leave a reply

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