Triangle abc is transformed with the center of dilation at the origin. pre-image: △abc with vertices a(2, 5), b(6, 10), c(9, −1) image: △a′b′c′ with vertices a′(0.5, 1.25), b′(1.5, 2.5), c′(2.25, −0.25) what is the scale factor of the dilation that maps the pre-image to the image? enter your answer in the box.