Question

( n-2) (4n-1) (5n+2) form an arithmetic sequence . find n. find its fourth and fifth terms​

Answer 1

since the terms form an AP

4n - 1 - ( n - 2) = 5n + 2 - (4n - 1)

4n - 1 - n + 2 = 5n + 2 - 4n + 1

3n + 1 = n + 3

3n - n = 3 - 1

2n = 2

n = 1

so, the terms are

-1, 3, 7

d = 3 - (-1) = 3+1 = 4

a= -1

fourth term = 7+4 = 11

fifth term = 11+4 = 15