How can you tell whether an exponential equation models growth or decay? Use the general form of an exponential expression to explain your answer.

Step-by-step explanation:

The general form of an exponential equation for growth is

y= ( 1 + r ) ^x

and for decay is

y= ( 1 - r ) ^x

In general, if the number inside the parenthesis (the growth or decay rate) is greater than 1, it's a growth problem.  If the number inside the parenthesis is greater than 0 but less than 1 (in other words a positive fraction), it's a decay problem.