Answer:
D
Explanation:
1. Replace "f(x)" with "y:" y = (x + 1)/x
2. Interchange x and y: x = (y + 1)/y
3. Solve this result for y: 1
xy = y + 1, or xy - y = 1, or y(x -1) = 1, or y = --------
x-1
4. Replace "y" with:
-1 x
f (x) = ----------- This matches answer choice D.
x - 1