tentukan hasil dari 2+4+6+8+10+....100

Materi Barisan

Kelompokkan dgn sifat asosiatif
= (2 + 98) + (4 + 96) + ... + (48 + 52) + 50 + 100
= (100 × 24) + 150 = 2400 + 150 = 2550

2+4+6+8+10+...+100
a = 2
b = 4-2 = 2
n = 100/2 = 50

Sn = 1/2(n)[2a + (n - 1)b]
S50 = 1/2(50)[2(2) + (50 - 1)×2]
S50 = 25[4 + 49×2]
S50 = 25[4 + 98]
S50 = 25 × 102
S50 = 2550