Answer:
the function is linear
Explanation:
now you figure this out in many ways,
but the easiest is to plot the points on a Cartesian x-y plane, rule a line through the points,if it's in a straight line then its linear if it's a curve its cubic
from the question, after plotting your points.ie (-9,-2),(-5,-7),(-1,-12),(3-17)
we get a straight line pointing downwards.
I hope this is convenient enough