Question

Tentuka jumlah 25 bilangan ganjil yamg pertama

Answer 1

A = 1
b = 3-1 = 2
maka,
U25
= a+24b
= 1+24.2
= 1+48
= 49
jadi,
S25
= n/2 (a+Un)
= 25/2 (1+U25)
= 25/2 (1+49)
= 25/2 (50)
= 25 x 25
= 625