Question

For what value of K will K+9,2K-1,2k+7 be the consecutive terms of an A. P

Answer 1

Let, k + 9 = a 2k - 1 = b 2k + 7 = c  To be in AP,  a + c = 2b (k + 9) + (2k + 7) = 2(2k - 1) k + 9 + 2k + 7 = 4k - 2 3k + 16 = 4k - 2 3k - 4k = - 2 - 16  - k = - 18 k = 18  For k = 18, the terms k+9 , 2k - 1 , 2k + 7 are in AP

Answer 2

Answer:

Step-by-step explanation:

We have, k + 9, 2k + 1 and 2k + 7 as consecutive terms of an A.P

Then, 2(2k + 1) = k + 9 + 2k + 7

[If a,b and c are in A.P then 2b = a + c]

4k + 2 = 3k + 16

k = 18.

Answer