Question

4th term of an arithmetic sequence is 35 and its common difference is 8.
Find its first term. Find the term difference of 10th term and 20th term of the sequence

Answer 1

Answer:

an = a1 + (n-1)d

18 = a1 + (5-1)d

27 = a1 + (8-1)d

so

-9 = -3d

d = 3

then a1 = 18 - 12 = 6

so

an = 6 + (n-1)3