Now that we know how to use 1 rand 1 r to write percent growth and decay equations we can use this to determine the rate of change of a given equation 1 You make an investment where the balance over time can be modeled by the equation y 32000 1 035 where x represents the number of years since the investment started and y represents your total balance after x years a What is the starting balance of your investment b What is the rate of growth of your investment 2 y 100 0 96 is an equation that can be used to represent the purchasing power of 100 after x years of inflation What is the rate of inflation used to make this calculation