Toán Lớp 8: GIÚP em nx ạ tìm x biết 3x (x – 2) + x -2 = 0 em c.ơn trc ạ
Leave a reply
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.
Toán Lớp 8: GIÚP em nx ạ tìm x biết 3x (x – 2) + x -2 = 0 em c.ơn trc ạ
Comments ( 2 )
3x(x – 2) + x – 2 = 0
<=> 3x(x – 2) + (x – 2) = 0
<=> (x – 2)(3x + 1) = 0
=> \(\left[ \begin{array}{l}x – 2 = 0\\3x + 1 = 0\end{array} \right.\)
=> \(\left[ \begin{array}{l}x = 0 + 2\\3x = 0 – 1\end{array} \right.\)
=> \(\left[ \begin{array}{l}x = 2\\3x = -1\end{array} \right.\)
=> \(\left[ \begin{array}{l}x = 2\\x = – 1 : 3\end{array} \right.\)
=> $\left[\begin{matrix} x = 2\\ x = \dfrac{-1}{3}\end{matrix}\right.$
Vậy: x ∈ {2; (-1)/3}
3x ( x – 2 ) + x – 2 =0
⇒ 3x ( x – 2 ) + ( x -2 )=0
⇒ ( x – 2 ) ( 3x + 1 ) =0
⇒ \(\left[ \begin{array}{l}x – 2=0\\3x + 1=0\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=2\\x=-\dfrac{1}{3}\end{array} \right.\)
Vậy x ∈ { 2 ; -1/3 }