The answer is: -1/5 or -0.2
One side of the original triangle is 15 units long and the side of the equivalent side of the dilated triangle is 3 units long. Therefore the magnitude of the enlargement scale factor is 3/15 or 1/5;
The answer is -1/5 as the transformation resulted in an inversion as well as an enlargement/dilation, therefore the answer is negative.
