Answer: [tex]\frac{3}{4}[/tex]
Step-by-step explanation:
Given: Pre - image ABCD was dilated to produce image A"B"C"D'.
Let k be the scale factor of the dilation from Pre-image ABCD to A"B"C"D .
Since, the scale factor of dilation is the ration of the sides of the image to the pre-image.
Then,
[tex]k=\frac{\text{side of image}}{\text{side of the pre-image}}\\\\\Rightarrow\ k=\frac{9}{12}\\\\\Rightarrow\ k=\frac{3}{4}[/tex]
Hence, the scale factor for the dilation is [tex]\frac{3}{4}[/tex].