Dik : a = 5 r =2 Dit : a, 5 suku pertama barisan Geometri b, U15 c, S10

a. S5 = a (r^n - 1) : r - 1
S5 = 5 (2^5 - 1) : 2 - 1
S5 = 5 (32 - 1)
S5 = 5 (31)
S5 = 155

b. U15 = ar^14
U15 = (5)(2)^14
U15 = (5)(16.364)
U15 = 81.820

c. S10 = a (r^n - 1) : r - 1
S10 = 5 (2^10 - 1) : 2 - 1
S10 = 5 (1024 - 1) : 1
S10 = 5 (1023)
S10 = 5.115