Question

for what value of k will k+9, 2k-1 and 2k+7 are consecative term of an AP

Answer 1

let a1=k+9,a2=2k-1,a3=2k+7

if they are in ap

d=a2-a1

=2k-1-(k+9)

=k-10

d=a3-a2

=2k+7-(2k-1)

=6

both the d values are same so

k-10=6

k=16