Jumlah dari deret: 2 + 5 + 25/2 + .... + 3125/16 adalah... a). 324 3/16 b). 324 1/16 c). 544 3/16 d). 544 1/16 Pakai Cara ya...

u1 = a = 2
b = 5/2


un = a*b^(n-1)

3125/16 = 2*(5/2)^(n-1)

3125/32 = (5/2)^(n-1)

(5/2)log (3125/32) = n-1

5 * (5/2)log (3125/32) = n-1

n = 5 + 1 = 6

sn =( a(r^n - 1))/(r^n -1)
S6 = (2((5/2)^(6) - 1))/((5/2)- 1)
s6 = 2(15625/64 - 1)/( 3/2)
= (15561/32)/(3/2)
= 5187/16 = 324 3/16

jawabannya A