Answer:
- 3108
Explanation:
The sum to n terms of an arithmetic series is
= [ 2 + (n - 1)d ]
Substitute the given values into the formula
= [ (2 × - 26) + (23 × - 9) ]
= 12 ( - 52 - 207 )
= 12 × - 259 = - 3108
5.6m questions
7.4m answers
= 
[ 2
+ (n - 1)d ]
= 
[ (2 × - 26) + (23 × - 9) ]