Tyler has already taken 35 credit hours and plans on taking 15 hours per semester until he graduates. Does this describe a linear or exponential function?

Given:
Tyler has already taken 35 credit hours.
He plans on taking 15 hours per semester.
Let the number of semesters = x
So, the function that describes this will be:
[tex]y=15x+35[/tex]So, the function represents a line.
So, the answer will be a Linear function.