Answer:
quadratic
Explanation:
The x-values are sequential, so we can look at the y-values.
Differences from one to the next are ...
-7, -1, 5, 11, 17
And the differences of these numbers are ...
6, 6, 6, 6
When second differences are constant, the sequence can be produced by a second-degree (quadratic) polynomial.
__
Here, that polynomial is ...
y = 3x² +2x -1
The regression functions of a graphing calculator can help you find the appropriate formula.