Using bisection search to determine

Question

I have posted other thread but it did not receive answers thus i\'m trying to provide some of my work to make more clear.

I need to use bisection method to determine

Answer 1

This is the key:

while abs(x) > epsilon:
    x = balance
    for month in range(0, 12):
        x = (x - ans) * (1+monthly_interest)

Answer 2

remember to round to 2 decimal places otherwise MITx will not accept the answer