1)x/2x-6 + x/2x+2 = 2x/(x+1)(x-3).

1 bình luận về “1)x/2x-6 + x/2x+2 = 2x/(x+1)(x-3).”

1. x/(2x-6) + x/(2x+2) = (2x)/((x+1)(x-3)) ( ĐKXĐ : x \ne 3 ; x \ne – 1 )

   <=> (x(x+1))/(2(x+1)(x-3)) + (x(x-3))/(2(x+1)(x-3)) = (4x)/(2(x+1)(x-3)) 

   => x(x+1) + x(x-3) = 4x

   <=> x^2 + x + x^2 – 3x – 4x = 0

   <=> 2x^2 -6x  = 0

   <=> 2x(x – 3 ) = 0

   <=>  $\left[\begin{matrix} 2x=0\\ x-3=0\end{matrix}\right.$

   <=> $\left[\begin{matrix} x=0\;\text{(t/m)}\\ x=3\;\text{(loại)}\end{matrix}\right.$

   Vậy S = {  0 }

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