please help me i honest to god don't know what I'm doing

Answer:
[tex]a_1[/tex]=1,
[tex]a_n=a_n_-_1(-7)[/tex]
Step-by-step explanation:
I was learning this a few years back, 9th grade I think, it's not really difficult, a tip that I will give you is to search up a video explaining the variables in the formula of both recursive and explicit.
I'm sure that you can do it and do well on your tests, good luck!
Hope this helped! :)