If the point $(2,9)$ is on the graph of $y=f(x)$, then there is one point which must be on the graph of $y=f(-x)$. What is the sum of that point's coordinates?
f(-x) reflects the graph of f(x) across the y axis.....the x coordinate becomes - 2 and the y coordinate remains the same
So....the point (-2, 9) is on the graph of f(-x) and the sum of these coordinates is 7
