Respuesta :

jcherry99

Answer:

Step-by-step explanation:

Find the last term of the sequence.

a1 = 8

d = -7

n = 30

a30 = 8 + (n - 1)*(-7)

a30 = 8 + (30 - 1)*-7

a30 = 8 + 29*-7

a30 = 8 - 203

a30 = -195

Sum = (a + L)*n/2

Sum = (8 + -195) * 30/2

Sum = - 187  * 15

Sum = - 2805