We have a pre-image that is the point (4, 5).
We applied a dilation with scale 0.5 and center at (1, 6).
As the center is not the center of coordinates, we applied a change of coordinates to make (1, 6) the center of coordinates.
Then, the point (4, 5) becomes:

We apply the dilation to the point and get:

Now, we go back to the original coordinates:

We can verify the transformation in a graph:
The graph makes sense, as the image point is half the distance from the center of dilation that the pre-image point.