F4maths 問題

f(x) = Q(x)(x - 1)

f(2x + 1) = Q(2x + 1)(2x + 1 - 1)

f(2x + 1) = 2xQ(2x + 1)

So, x should be a factor of f(2x+1) (A)

Let f(x) be a polynomial.If f(x) is divisible by 2-1,which of the following must be a factor of f(2x+1)?
???
f(x) is of course divisible by 2-1
???
If 2-1 means (x - 1) then myisland8132 is correct.
If 2-1 means (2x - 1) then a, b, c, d are all wrong
If 2-1 means (2 - x) then c is correct.