help please

f(x)  =  g (g(x))

g (g (x))    means that we sub g(x) into itself....so we have that

g(g(x) ) = 2 (2x - 1) - 1  =

4x - 2 - 1  =

4x - 3

So....since this is  f(x)

Then f(3)  =

4(3)  - 3  =

12 - 3  =

9

I am using AoPs when I typed in 9 as the ansswer it said it was incorrect

Chris just forgot the -g(x) portion of f(x)

so he got 9 fpr the first part...

9 - (2(3)-1)

9-6+1 = 4