Given that (-9,3) is on a graph of f(x), find the corresponding point for the function f(-3x)

For a function f(x), f(-x) is the reflection of f(x) along y-axis.
f(Cx) compresses the function in x direction.

So, f(-3x) involves two transformation. 

1) Compression in x direction by a factor of 3.
This means the value which was first occurring at x=-9 will now occur at x=-3

2) Reflection along y-axis.
This means, the value which was first occur at x=-3, will occur at x=3

So, the point (-9, 3) on graph of f(x) will become (3,3) on the graph of f(-3x).

Where is the problems