<h2>3</h2>
Step-by-step explanation:
The equation of line passing through the two points is 
When substituted,the equation becomes 
which when simplified is 
The line clearly passes through origin.
The distance between two points is 
Distance between origin and  is
 is  .
.
Distance between origin and  is
 is 
Scale factor is  
So,scale factor is 
which when simplified becomes 3.