## Elementary Algebra

The interest formula is: interest due = principal $\times$ yearly rate of return $\times$ time in years. This formula can be written as i = P $\times$ r $\times$ t. P = 3500 r = 5.25% t = 2 Substitute these values into the formula to find out how much interest is due. i = 3500 $\times$ 5.25% $\times$ 2 i = 3500 $\times$ 0.0525 $\times$ 2 i = 367.5 367.5 dollars of interest is due.