Tolong di jawab, besok senin di kumpulin. 1. Hitunglah Sn dari deret geometri berikut a.1/16+1/4+1+... (n=8) b.20+10+5+... (n=10)

a. Sn = U1 (rⁿ - 1)/r-1
S8 = 1/16 (4^8 - 1)/4-1
= 1/16 (65.536 - 1)/3
= 1/16 x 65.535 / 3
= 65.535/16 /3
= 65.535/16 x 1/3
= 65.535/48
= 1365 15/48
= 1365 5/16

b. Sn = U1 (rⁿ - 1)/r-1
S10 = 20 ((½)^10 - 1)/ 1/2 - 1
= 20 (1/1.024 - 1)/ -½
= 20 (-1.023/1.024) / -½
= -20.460/1.024 / -½
= 20.460/1.024 / ½
= 20.460/1.024 x 2/1
= 40.920/1.024
= 39 984/1024
= 39 123/128

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