To subtract vectors, you simply have to subtract correspondent coordinates.
So, if you have

the subtraction is simply

So, in your case, we have

 
        
             
        
        
        
The range is 11- 3 = 8  Adding 5 would not affect the range.
        
             
        
        
        
Answer:
12 cm of coastline
Step-by-step explanation:
Multiply the years (factor) by the receding amount, 3cm, (constant) BAM answer.