What is the sum of the first 47 terms of the sequence? -215, -201, -187, -173, ...​

5029

Step-by-step explanation:

There is a common difference between consecutive terms, that is

d = - 201 - (- 215) = - 187 - (- 201) = - 173 - (- 187) = 14

This indicates the sequence is arithmetic with sum to n term

=  [ 2a₁ + (n - 1)d ]

where a₁ is the first term and d the common difference

Here a₁ = - 215 and d = 14 , then

=  [ (2 × - 215) + (46 × 14) ]

    = 23.5 (- 430 + 644)

   = 23.5 × 214

   = 5029