Answer: −2 and −1/2.
Step-by-step explanation:
A dilation is a transformation of a geometric image that is known to change its size but not the shape.
The size of the figure basically depends on the scale factor (k) .
When k >1 , then there would be expansion.
When k<1 , then there would be contraction.
When k=1 , then no change in size.
i.e. For contraction , the scale factor (k) must be negative.
From the given options , the scale factors produce a contraction under a dilation of the original image would be −2 and −1/2.
Hence,the correct answers are : −2 and −1/2.