Question

Find the value of k so that 3k+7 2k+5 2k7 are in ap

Answer 1

Let a1 = 3k+7
a2 = 2k+5
a3 = 2k+7
Since in AP a2 - a1 = a3 - a2 (1)
so, a2 - a1 is
(2k+5) - (3k+7) = -k - 2
and, a3 - a2 is
(2k+7) - (2k+5) = 2
Now by (1)
-k - 2 = 2
-k = 4
k = -4

So, the terms are -5 , -3 and -1.

Answer 2

hope you know how to do it