Question

find the value of k so that 8k+4,6k-2 and 2k-7 will form A.P

Answer 1

Let a= 8k + 4 b = 6k - 2 and c= 2k -7

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

2( 6k - 2) = (8k +4)(2k - 7)

12 k - 4. = 16k^2 - 56k + 8k - 28

16k^2 - 60k - 24 =0

4(4k^2 -15k - 6)=0

4k^2 -15 k - 6=0

k = (- 15+ √321)/8 or (-15 - √321)/8

Hope this solution will help you