I totally forgot how to do recursive formulas

one of the questions gives:
4th term is 3; 20th term is 35
1.) Give first term
2.)give common difference
3.) give recursive formula
4.) give formula for nth term

if anyone could teach me i'd be great

since it mentions "common difference", i assume it's of the form:
f(n) = f(n-1) + x

and you know f(4) = 3 and f(20) = 35.

so you can see it increased by 32 from n = 4 to n = 20.

does that give you a starting place so you can finish it yourself?

yes thank you, i just looked at notes and figured it out after a bit lol