5/6 is greater. 
2/3 < 5/6
        
             
        
        
        
Answer:
- not possible:  1, 2, 4, 5, 8, 11
- possible: all others
Step-by-step explanation:
Obviously, all multiples of 3 and 7 can be paid.
1 cent can be added by adding a 7-cent stamp and taking away two 3-cent stamps. 2 cents can be added by adding three 3-cent stamps and taking away one 7-cent stamp. Hence any value more than 7 +2(3) = 13 cents can always be accommodated.
Amounts that are impossible:
   1, 2, 4, 5, 8, 11 cents
All other positive integer amounts are possible.
 
        
             
        
        
        
Answer:
7x+2z+16
Step-by-step explanation:
find like terms
7 9
add them 
7+9=16
7x+2z+16
 
        
             
        
        
        
Answer:
12m^2+14m
Step-by-step explanation:
The "^means exponet" Hope I made your day
:)