Answer
Scale factor = (2/5)
Explanation
The scale factor shows the extent to which the original image has been dilated (enlarged or reduced). It is given mathematically as
[tex]\text{Scale factor = }\frac{Length\text{ of a side of the image}}{Length\text{ of the corresponding side of the original figure}}[/tex]From the image attached we can see that
Length of a side of the image = 4 dots
Length of the corresponding side of the original image = 10 dots
Scale factor = (4/10) = (2/5)
Hope this Helps!!!
