1+3+5+7+9+....+99 tolong jawab sskarang

a = 1
b = 3 - 1 = 2
n = 100/2 = 50


Sn = 1/2(n)[2a + (n - 1)b]
S50 = 1/2(50)[2(1) + (50 - 1)×2]
S50 = 25[2 + 49 × 2]
S50 = 25[2 + 98]
S50 = 25 × 100
S50 = 2500

Jadi jumlah barisan itu adalah 2500