Answer:
GCF= 1
LCM= 1680
Step-by-step explanation:
GCF= Find the prime factorization of 21, 21 = 3 x 7 
Find the prime factorization of 80, 80 = 2 x 2 x 2 x 2 x 5 
Then multiply the prime factors both numbers have in common 
LCM= multiply the two numbers together and ignore all negative signs
 
        
             
        
        
        
If one foot is equivalent to 0.3048 meters, then <span>0.3048 x 65 feet should give us our answer.
</span>0.3048 x 65 feet = 19.812.
19.812 rounded to the nearest tenth is 19.8.
        
             
        
        
        
(3x+4) units.
Working;
AM=AD+DM
      =x+5+2x-1
      =(3x+4) units