Present value: If you invest P dollars (the present value of your investment) in a fund that pays an interest rate of r, as a decimal, compounded yearly, then after t years your investment will have a...

Present value: If you invest P dollars (the present value of your investment) in a fund that pays an interest rate of r, as a decimal, compounded yearly, then after t years your investment will have a value F dollars, which is known as the future value. The discount rate D for such an investment is given by

where t is the life, in years, of the investment. The present value of an investment is the product of the future value and the discount rate. Find a formula that gives the present value in terms of the future value, the interest rate, and the life of the investment.