tolongin donk ka buat besok dikumlpulin, yg benar jawabannya+caranya. terima kasih

Bab Barisan dan Deret
Matematika SMP Kelas IX

geometri
r = 9/3
r = 3

Un = a x rⁿ⁻¹ = 729
3 x 3ⁿ⁻¹ = 729
3 x 3ⁿ x 3⁻¹ = 3⁶
3ⁿ = 3⁶
n = 6

Sn = a x (rⁿ - 1) / (r - 1)
S6 = 3 x (3⁶ - 1) / (3 - 1)
S6 = 3 x 728 / 2
S6 = 1.092