dikethui suatu deret aritmatika 8+6+4 maka jumlah 8 suku pertamanya

Materi : Barisan dan Deret
Kelas : IX SMP

8 + 6 + 4 + ... + ...

a = 8
b = -2

Sn = n/2 ( 2. a + (n - 1) b)
S8 = 8/2 ( 2(8) + (8 - 1) (-2))
S8 = 4 (16 + 7 ( -2))
S8 = 4(16 - 14)
S8 = 4 ( 2 )
S8 = 8

a = 8
b = 2

Sn = n/2 (2.a (n-1) b)

S8 = 8/2 (2.8 (8-1) 2)

S8 = 8/2 (16.7.2)

S8 = 8/2 (16.14)

S8 = 8/2. 224

    = 896