Constructing Linear and Exponential Functions Practice Test

Determine whether the relationship is linear or exponential, then write the function. The table gives:

$x$: 1, 2, 3, 4

$y$: 2, 6, 18, 54

Which function models the data?

The geometric sequence is $5, 15, 45, 135, \dots$ where the term number is $x$ (so $x=1$ gives 5). Write an exponential function $g(x)$ that gives the $x$th term.