2x ²-2=x(x-1) Giai phuong trinh

2 bình luận về “2x ²-2=x(x-1) Giai phuong trinh”

1. #wdr

   2x^2-2=x(x-1)

   <=> 2x^2 -2 =x^2-x

   <=>2x^2 -x^2 +x=2

   <=> x^2-x -2=0

   <=> x^2 +x-2x-2=0

   <=> x(x+1) -2(x+1)=0

   <=> (x-2)(x+1)=0

   TH1: x-2=0

    <=> x=2

   TH2: x+1=0

   <=> x=-1

   => S={2;-1}

   Trả lời
2. 2x^2 – 2 = x(x -1)

   <=> 2x^2 – 2 – x^2 + x = 0

   <=> x^2 + x – 2 = 0

   <=> x^2 – x + 2x – 2 = 0

   <=> x(x – 1) + 2(x -1)= 0

   <=> (x +2)(x -1) = 0

   <=> \(\left[ \begin{array}{l}x+2=0\\x-1=0\end{array} \right.\) 

   <=> \(\left[ \begin{array}{l}x=-2\\x=1\end{array} \right.\) 

   Vậy S = {-2;1}

   Trả lời