1/16+1/8+1/4+...+16 tentukan jumlah suku ke n barisan tersebut

jwb
a=1/16
r = 2
Un   = 16
a rⁿ⁻¹  = 16
1/16  (2)ⁿ⁻¹  = 16
(2)ⁿ⁻¹  = 16² = 2⁸
n - 1= 8
n = 9

Sn = a. (rⁿ -1) /(r -1)
S9 = 1/16 (2⁹ -1) /(2-1)
S9 = 2⁻⁴ (2⁹ - 1) = 2⁵ - 2⁻⁴ = 32 - 1/16 = 31 ¹⁵/₁₆