Question

Can anyone help me with question no 11

Answer 1

Step-by-step explanation:

tn = Sn - S(n - 1)

tn = 3(4ⁿ - 1) - 3(4ⁿ⁻¹- 1)

=> 3*4ⁿ - 3 - [3*4ⁿ⁻¹ - 3 ]

=> 3*4ⁿ - 3 - 3*4ⁿ⁻¹ + 3

=> 3*4ⁿ - 3*4ⁿ⁻¹

=> 3*4ⁿ - 3*4ⁿ*4⁻¹

=> 3*4ⁿ [1 - 1/4]

=> 3*4ⁿ*3/4

=> 3*4ⁿ*3 * 1/4

=> 3*3*4ⁿ*4⁻¹

=> 9(4ⁿ⁻¹) => option D