Equation of exponential growth:

Here Y  is the final amount.

a is the initial amount.

r is the rate of change expressed as a decimal, r > 0.

t is time.

a. Write an equation for the number of memberships sold at Work-Out Gym t years after 2001.

                     (Substitute )

                      (Add: )

b. If this trend continues, predict how many membership the gym will sell in 2020.

                   (Substitute )

     (Use exponent calculator:)

              (Multiply: )

a. Write an equation for the number of memberships sold at Work-Out Gym t years after 2001 is .

b. If this trend continues, predict how many membership the gym will sell in 2020 is .