Question

What is the 25th term of the arithmetic sequence where a1 = 8 and a9 = 48 ?

Answer 1

Do u know the formula?

Answer 2

Allow me to explain this. You first have to find the common difference. I don't remember the formula for finding the difference between two separate numbers, but in this case it's d=5 (Sorry for the spoiler). Now plug that into the formula:
\[a _{n}=a _{1}+(n-1)d\]

Hope this helps :)