dhs
posted by madog .
Amanda bought a car for $8,500. Her loan was for five years at a 4.6% interest rate. How much will Amanda pay for her car total, including interest?

I = PRT
I = 8,500 * 0.046 * 5
Add the interest to the principal. 
8,500$ car, wow
So if the interest rate is 4.6% for 5 years, she has to pay that percentage of the total cost each year. There is an equation for this, but to make it simpler ill tell you it this way:
8500 Initial cost
8500*1.046 cost after 1 year
=8891
8891*1.046 Cost after 2 years
=9299.986
And so continue on until you get to 5 years. 
Mrs sue put the equation for a interest that was put to the initial price and collected annually, this is not what the question is asking for.