Step-by-step explanation:
From the statement: 
M: is total to be memorized 
A(t): the amount memorized.
The key issue is translate this statement as equation "rate at which a subject is memorized is assumed to be proportional to the amount that is left to be memorized"
memorizing rate is 
.
the amount that is left to be memorized can be expressed as the total minus the amount memorized, that is 
.
So we can write

And that would be the differential equation for A(t).
 
        
             
        
        
        
Answer:
growth 
Step-by-step explanation:
 
        
             
        
        
        
Answer:
x>6
Step-by-step explanation:
3x+12-5x+5<5
-2x+17<5
-2x<-12
x>6