Triangle abc is transformed with the center of dilation at the origin. pre-image: △abc with vertices a(−5, −4), b(−7, 3), c(3, −2) image: △a′b′c′ with vertices a′(−3.75, −3), b′(−5.25, 2.25), c′(2.25, −1.5) what is the scale factor of the dilation that maps the pre-image to the image?