Difference means you want to find the change between two, thus u subtract between both of it.
m-2
        
                    
             
        
        
        
Answer: The answers are 
- Subtract 7 from both sides of the equation.
- Subtract 7 from 7.
- Substitute 5 for p to check the solution.
Step-by-step explanation:
p + 7 = 12
=   p + 7 - 7 = 12 - 7
=   p = 5
Then for the substituting part
5 + 7 = 12
Hope this helps!
 
        
             
        
        
        
48: 1, 2, 3, 4, 6, 8, 12, 16, 24, 48
54: 1, 2, 3, 6, 9, 18, 27, 54
gcf: 6