Question

Which one is a rule for the nth term of an arithmetic sequence with a8 = 56 and d = 5?

Answer 1

a1+(n-1)d

Answer 2

The formula for arithmetic sequence is:

\(\Large \color{MidnightBlue}{\Rightarrow a_{n} = a_{1} + (n - 1)d }\)

\(\Large \color{MidnightBlue}{\Rightarrow a_{n} = a_1 + (n - 1)5 }\)

Answer 3

a1 would be 56 - (5 * 8) = 16

Answer 4

a1=first term
an=last term
n= term such as a8 n=8
d=difference

so the way you applied it is wrong is it not, @parth?