Tentukan hasil dari tanpa menghitung satu persatu -100-99-98...-2-1-0+1+2+....+48+49+50

-100 - 99 - 98 - ... - 2 - 1 - 0 + 1 + 2 + ... + 48 + 49 + 50
a = bilangan awal = -100
b = beda = -99 - (-100) = -99 + 100 = 1

Un = 50
a + (n - 1)b = 50
-100 + (n - 1)(1) = 50
-100 + n - 1 = 50
-101 + n = 50
n = 50 + 101
n = 151

Sn = (n ÷ 2)(a + Un)
S₁₅₁ = (151 ÷ 2)(-100 + 50)
      = (75,5)(-50)
      = -3.775

-100 - 99 - 98 - ... - 2 - 1 - 0 + 1 + 2 + ... + 48 + 49 + 50 = -3.775