The given function is linear, and it can also be expressed as
The given function is linear because the starting value is being added and the common difference is being multiplied.
There are two functions; linear and exponential. A linear function is one that has a common difference (which means it is being added or subtracted), and on a graph it will be a straight line.
An exponential function, however, is one that has a common ratio (which means it is being multiplied), and on a graph it will be a curved line.
The function notation for a linear equation is
while the exponential equation would be
In this problem, the starting value,
It is technically already in the form