Triangle abc is transformed with the center of dilation at the origin.

pre-image: △abc with vertices a(−3, 4), b(−1, 12), c(4, −2)

image: △a'b'c' with vertices a'(−0.6, 0.8), b'(−0.2, 2.4), c'(0.8, −0.4)

what is the scale factor of the dilation that maps the pre-image to the image?

enter your answer in the box.

The correct for this question is this one: 1:25 

Pre-image △ABC has vertices A(−3, 4), B(−1, 12), C(4, −2)
Final Image △A'B'C' has vertices A'(−0.6, 0.8), B'(−0.2, 2.4), C'(0.8, −0.4)

Pre-image has an area of 34 square units
Final Image has an area of 1.36 square units.

Based from the area,
dilation = 34 / 1.36
dilation = 25