Bantu saya mengisi 2+4+6+8+10…..100​

Un = a + (n-1)b

100 = 2 + (n-1) 2

98 = 2n – 2

100 = 2n

n = 50

Sn = n/2 (a + Un)

S50 = 50/2 (2 + 100)

S50 = 25(102)

S50 = 2550