Question

For what the of k will k+9 , 2k-1 ,
2k+7 are three consecutive term of ap

Answer 1

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

d = a2-a1
= a3-a2
therefore, 2k+7-2k +1 = 2k -1-k-9
8= k-10
k=18

Answer 2

The value of k is 18 ...