Question

Please hellppppp

Find the first, fourth, and eighth terms of the sequence.

A(n) = −5 ∙ 2x − 1


a. 1; –1,000; –10,000,000


b. –10; –80; –1,280


c. –20; –160; –2,560


d. –5; –40; –640

Answer 1

Answer: d) -5, -40, -640

Explanation:

`A_n=-5\cdot 2^(x-1)\\\\A_1=-5\cdot 2^(1-1)\\\\.\quad=-5\cdot 2^0\\\\.\quad=-5\cdot 1\\\\.\quad=-5\\\\\\\\A_4=-5\cdot 2^(4-1)\\\\.\quad=-5\cdot 2^3\\\\.\quad=-5\cdot 8\\\\.\quad=-40\\\\\\\\A_8=-5\cdot 2^(8-1)\\\\.\quad=-5\cdot 2^7\\\\.\quad=-5\cdot 128\\\\.\quad=-640`