Question

xy-x-y+1 除以 y的2次方－2y＋1 谢谢大家啊!, 很急啊! 拜托了

Answer 1

(xy-x-y+1)/(y^2-2y+1)=[x(y-1)-(y-1)]/(y-1)^2=(y-1)(x-1)/(y-1)^2=(x-1)/(y-1)