D. If the scale factor for the dilation of the figure is 0.9, then the dilation is an enlargement

Option C.

Step-by-step explanation:

Suppose that we have a point (x, y)

If we do a dilation with a center in the origin of scale factor K, then the new coordinates of our point will be:

(k*x, k*y)

If k > 1, we have an elargement.

if 0 < k < 1, we have the opposite case.

Now, suppose that one random vertex of the preimage is A (a, b)

Then after we do the dilation, the new coordinate of this vertex will be:

A' = (k*a, k*b)  (this is, the original coordinates multiplied by the scale factor)

And this will happen for all points actually, so particularly the corresponding coordinates of the vertices of the image are the vertices of the preimage multiplied by the scale factor.

Then the correct option is C

the entire expression should be subtracted from 30. to subtract the quantity, distribute the negative sign, which changes the signs on the terms. so, the –2 changes to positive and gets added to 30 instead of subtracted from it.

hope this ! ^w^

good luck on your studies! : )

david edward.