Thực hiện phép trừ :
\(\dfrac{2x}{x-1}-\dfrac{x}{x-1}-\dfrac{1}{x-1}\)
Cách thực hiện nào sau đây sai ?
(A) \(\dfrac{2x}{x-1}-\dfrac{x}{x-1}-\dfrac{1}{x-1}=\left(\dfrac{2x}{x-1}-\dfrac{x}{x-1}\right)-\dfrac{1}{x-1}=......................\)
(B) \(\dfrac{2x}{x-1}-\dfrac{x}{x-1}-\dfrac{1}{x-1}=\dfrac{2x}{x-1}-\left(\dfrac{x}{x-1}-\dfrac{1}{x-1}=..............\right)\)
(C) \(\dfrac{2x}{x-1}-\dfrac{x}{x-1}-\dfrac{1}{x-1}=\dfrac{2x}{x-1}-\left(\dfrac{x}{x-1}+\dfrac{1}{x-1}\right)=........\)
(D) \(\dfrac{2x}{x-1}-\dfrac{x}{x-1}-\dfrac{1}{x-1}=\dfrac{2x}{x-1}+\dfrac{-x}{x-1}+\dfrac{-1}{x-1}=.........\)