Suppose you have ab on a coordinate plane located at a(-3,-4) and b(5,-4). under a dilation centered at (9,0), ab becomes a'b' with coordinates a'(6,-1) and b'(8,-1). what is the scale factor for this dilation

The distace between the center of dilation and point a is diven by:



The distance between the center of dilation and point a' is given by:



It can be seen that the distance from the center of dilation to the image is 1/4 times the distance from the centre of dilation to the preimage.

Therefore, the scale factor is 1/4.

In this problem it decreased 20%