3/4b-1/6=1/2×b
1.75b=.3
b=0.2
I believe this is right. But not 100%
        
             
        
        
        
Answer:
Since we do not know the balance we should start with, a general answer:

598 - 47,27 = 550,73, assuming b_old was 0$ for your example
Step-by-step explanation:
b stands for balance (old - before any deposits or withdrawals, new after all done)
d for deposits 
w for withdrawals
 
        
             
        
        
        
Answer:
Rate of change = (1350 - 750)/(2010 - 2000) = 600/10 = $60
Initial value = $750
Equation is y = 60x + 750; where y is the amount charged to customer and x is the number of years from 2000.