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 : a, 2 (x+3) – x² – 3x = 0 b, ( 2x + 1 )² – ( x – 1 )² =0 c, x² – 4x + 3 = 0

Toán Lớp 8: tìm x :
a, 2 (x+3) – x² – 3x = 0
b, ( 2x + 1 )² – ( x – 1 )² =0
c, x² – 4x + 3 = 0

Comments ( 2 )

  1. Giải đáp+Lời giải và giải thích chi tiết:
     a) 2(x+3)-x^2-3x=0
    <=>2(x+3)-x(x+3)=0
    <=>(x+3)(2-x)=0
    <=>$\left[\begin{matrix} x+3=0\\ 2-x=0\end{matrix}\right.$
    <=>$\left[\begin{matrix} x=-3\\ x=2\end{matrix}\right.$
     Vậy x=-3 hoặc x=2
     b) (2x+1)^2-(x-1)^2=0
    <=>(2x+1-x+1)(2x+1+x-1)=0
    <=>(x+2)3x=0
    <=>$\left[\begin{matrix} x+2=0\\ 3x=0\end{matrix}\right.$
    <=>$\left[\begin{matrix} x=-2\\ x=0\end{matrix}\right.$
      Vậy x=-2 hoặc x=0
     c) x^2-4x+3=0
    <=>x^2-3x-x+3=0
    <=>x(x-3)-(x-3)=0
    <=>(x-3)(x-1)=0
    <=>$\left[\begin{matrix} x-3=0\\ x-1=0\end{matrix}\right.$
    <=>$\left[\begin{matrix} x=3\\ x=1\end{matrix}\right.$
      Vậy x=3 hoặc x=1

Leave a reply

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