From the information given, triangle M'S'V' was dilated to give triangle MSV. Since triangle MSV is an enlargement of triangle M'S.V, it means that the scale factor is greater than 1. To find the scale factor, we would find the ratio of the x and y coordiantes. We have
Scale factor = M/M' = - 3/- 2 = 3/2 = 1.5
Scale factor = 1.5