Question

n, 3n,5n, is an arithmetic sequence what is the common difference and find the 25th term

Answer 1

To find the common difference, just subtract the 1st term from the 2nd term.

So, 3n-n = 2n

Thus, 2n is the common difference.

Then use the arithmetic sequence formula to find the 25th term.

Given:

a_1 = n

n = 25

d = 2n

Find: a_25

Solution:

a_25 = a_1 + (n-1)d

a_25 = n + (25-1)(2n)

a_25 = n + (24)(2n)

a_25 = n + 48n

a_25 = 49n

FINAL ANSWER: 49n