Question

Barisan 1/2, 1/4, 1/8

tentukan :
a =
r =
S7 =

Answer 1

1/2, 1/4  , 1/8

a=S1= 1/2

r = 1/4 : 1/2 = 1/2

S7 = a r^6  = 1/2 x (1/2)^6  = 1/2 x 1/64 = 1/128

Answer 2

Barisan : 1/2, 1/4, 1/8, . . . .

Maka,
a = 1/2

r = 1/4 : 1/2
  = 1/2

S7 = a r^6
     = 1/2 x (1/2)^6
     = 1/2 x 1/64
     = 1/128