no 7 soal mtk peminatan sma kls 10

Perpangkatan

(3^(n+1) - 3^(n-1)) / (3^(n-1) - 3^(n-2))
= (3ⁿ . 3¹ - 3ⁿ . 3^-1) / (3ⁿ . 3^-1 - 3ⁿ . 3^-2)

= (3^n (3¹ - 3^-1)) / (3^n ( 3^-1 - 3^-2))
= (3 - 1/3) / (1/3 - 1/9)
= (8/3) / ( 2/9)
= 8/3 x 9/2
= 12

B.