(x-1)/x-2x/(x-1)=-1
两边乘以x(x-1)得(x-1)²-2x²=-x(x-1)
整理得3x=1
解得x=1
或移项
(x-1)/x=2x/(x-1)-1=(x+1)/(x-1)
即得(x-1)²=x(x+1)
整理得3x=1
解得x=1