题目用换元法解分式方程xx−1−2x−2x=1\frac{x}{x-1}-\frac{2x-2}{x}=1x−1x−x2x−2=1时,如果设xx−1=y\frac{x}{x-1}=yx−1x=y,那么原方程化为关于yyy的整式方程是（ ）A.y2−2y+1=0y^{2}-2y+1=0y2−2y+1=0B.y2−2y−1=0y^{2}-2y-1=0y2−2y−1=0C.y2+y−2=0y^{2}+y-2=0y2+y−2=0D.y2−y−2=0y^{2}-y-2=0y2−y−2=0知识点：换元法解分式方程章节：方程与不等式 / 分式方程
