find the sum of first 25 terms of the sequence 12,23,34-. Question find the sum of first 25 terms of the sequence 12,23,34….. in progress 0 Math Maria 1 month 2021-08-20T11:54:56+00:00 2021-08-20T11:54:56+00:00 1 Answer 0 views 0

## Answers ( )

Answer:12+23+34+45+56+67+78+89

This sum can be found quickly by taking the number n of terms being added (here 8), multiplying by the sum of the first and last number in the progression (here 12 + 89 = 101), and dividing by 2:

n(a1+an)

2

8(12+89)

2

The sum of the 8 members of this series is 404Step-by-step explanation: