tolong dibantu ya :)

f(x) = 2logx / (1- 2. 2logx)
   = 2log x / (2log 2 - 2log x^2)
   = 2 log x / 2log (2/x^2)
   = (2/x^2)log x

f(2/x) = (2/(2/x)^2) log (2/x)
   = (2/4/x^2) log 2/x
  = (x^2/2) log 2/x
  = (2/x^2)^-1log 2/x
  = -1.  (2/x^2log2/x)

f(x) + f(2/x) =  (2/x^2)log x + ( - (2/x^2log2/x)
   = (2/x^2) log (x / 2/x)
  = (2/x^2) log (x^2/2)
  = -1    (2/x^2)log 2/x^2
  = -1 .  1
  = -1
Jawaban C