Question

Tentukan jumlah dari pola bikangan berikut.
a.1,3,5,7,9,11,13,15,17,19,21,23,25
b.17 bilangan ganjil pertama

Answer 1

A. Sn = n/2 (2a + (n-1) b)
S13 = 13/2 (2.1 + (13-1) 2)
= 13/2 (2 + 12.2)
= 13/2 (2+24)
= 13/2.26
= 169

b. Sn = n/2 (2a + (n-1) b)
S17 = 17/2 (2.1 +  (17-1) 2)
= 17/2 ( 2 + 16.2)
= 17/2 (2 + 32)
=17/2.34
= 289