1. The problem statement, all variables and given/known data I need to solve a compound interest problem. Easy enough on it's own. However in this case 400 is taken away each month. So I used this formula: then subtracted this from it: (W x 12)t Where W is the amount withdrawn monthly, and then multiplied by twelve to make it an annual amount. The initial amount was 10000, the interest rate is 0.06, it gets compounded monthly, and the number of years is the unknown. So to solve for t I filled in the values: 0 = (10000(1-(0.06-12))^12t) - (400 X 12)t Then I did this: 48000t/10000 = 1-(0.06-12))^12t Which went down to: 4.8t = (0.995)^12t I tried logs and a few other random things, but nothing worked. How can I isolate t?