CE MATHS 2007 MC no.40 (15 points)

這是一條 "陷阱" 題目, 看似簡單但容易錯.
07MC題解 (40) 在以下網頁 :
會考數學MC詳解 :
http://www.takwing.idv.hk/studyroom/ce_maths/index.html
依個網主按年份逐題逐題解答, 真係好比心機, 你只要按年份再按題號, 便看到MC中文詳解, 希望幫到你la, 加油
圖片參考：http://tw.yimg.com/i/tw/ugc/rte/smiley_1.gif

I am not quite sure but are you sure that F(x)is divisible by x-1 not x+1?

f(1)=0
So you have to find a number that, when substitue into 2x-1, will become 1.
i.e. when x=1
so the answer should be x-1
which is not the answer

so 退而求其次, I'll guess it'll be x because put x=0, you will have f(-1)
That is the reason why I ask if it is x+1...