Question

find the sum of an AP of 17 terms whose middle term is 5

Answer 1

Answer:

85

Step-by-step explanation:

take the first term be a-8d and 17th term be a+8d

Answer 2

Answer:

so

n= 17

9th term = 5= a +8d

so d= 5-a/8

s= 17/2(2a+16×5-a/8)

=17/2×2a+10-2a

=17×5

=85