Answer: it's by 3. the scale factor decreases by 3.
Step-by-step explanation: the " ' " indicates that that is the new coordinate example " p' " is the new coordinate for "P" same with Q and R. On the y-axis is shows P going from 3 to 1 and that is saying 3/1. 3/1 is 3 which indicates that the scale factor is decreasing by 3.
