Question

Find the 40th term of the sequence 2, -12, 72,....

Write the arithmetic sequence that has 4 means between 5 and 15

Answer 1

\[a _{n}=a _{1}+(n-1)d\]

Answer 2

what is n and d?

Answer 3

n is the nth term, like the 40th term, d is the common difference. Not sure about your question; it seems like two different questions.

Answer 4

...