Answer:
In the figure we can see that the dilation is an enlargement from the black figure to the blue figure.
The factor would be found by taking two points and dividing them. For example, at the right side we have that the point was from x=2 to x=4, their division would be 4/2=2. Now, we take the point in the left side x=-1 and x=-2, if we divide them we have -2/-1=2.
Therefore, the scale factor is 2.