Question

1+3+5+7+9+ ... +99 (tanpa menghitung satu persatu) please jwb buat adikku

Answer 1

Deret Aritmetika,

awal = 1
beda = 2

Un = a + (n - 1)b
99 = 1 + (n - 1)2
99 = 1 + 2n - 2
99 = 2n - 1
2n = 99 + 1
2n = 100
n = 100/2
n = 50

Sn = n/2 (a + Un)
= 50/2 (1 + 99)
= 25(100)
= 2500

Answer 2

Sn=n/2 (a+un)
   =50/2 (1+99)
   =25 (100)
   = 2500