Answer: f(f(f(x)) = 8x - 7
Explanation:
f(f(x)) means that we are evaluating f(x) with itself, then if f(x) = 2x - 1
f(f(x)) = 2*f(x) - 1 = 2*(2x - 1) - 1 = 4x - 2 - 1 = 4x - 3
f(f(x)) = 4x - 3
Then, we have f(f(f(x)) = 4*f(x) - 3
= 4*(2x - 1) - 3 = 8x - 4 - 3 = 8x - 7