Answer:
30 days
Step-by-step explanation:
If d represents the number of daily withdrawals, then Aaron's bank balance (b) is given by ...
b = 500 -12d
We want to find d that corresponds to b=140, so we fill in that value and solve.
140 = 500 -12d
-360 = -12d . . . . . . subtract 500
30 = d . . . . . . . . . . . divide by -12
It will take 30 days to have $140 left in Arron's bank account.