HELPP 15 POINTS PLEASE PLEASE PLEASE

Answer:
a+(n-1)14
Step-by-step explanation:
ok so
a=the first number which is 16.50
n=the term.eg since 30.50 is the second number it's the second term
14 is the common difference d
I found 14 like this
30.50=16.50+(2-1)d
Therefore d=14
hence the formula is a+(n-1)14