Question

For an arithmetic sequence, 9th term is 16 and its 16th term is 9

a) what is the sum of first 49 terms? please answer me​

Answer 1

Answer:

0

Step-by-step explanation:

9th term =a+8d=16

16th term =a+15d=9

on solving above equations,

a=24, d= -1

so , sum of first 49 terms =n/2(a+l)

a=24, d= -1, l=a+48d= -24

sum=n/2(a+l)=0

Answer 2

Answer:

Answer = 0

an = a + ( n- 1 )d

by using elimination method solve it then

by sum formula we get 0 as Answer