Question

Find the first, fourth, and eighth terms of the sequence. A(n) = −5 ∙ 2x − 1

Answer 1

Answer:

The first option.

Step-by-step explanation:

The first term of the sequence would be...

A(1) = -5 * 2^(1 - 1)

= -5 * 2^0

= -5 * 1

= -5

The fourth would be...

A(4) = -5 * 2^(4 - 1)

= -5 * 2^3

= -5 * 8

= -40

The eighth would be...

A(8) = -5 * 2^(8 - 1)

= -5 * 2^7

= -5 * 128

= -640

So, the correct answer is the first option.

Hope this helps!

Answer 2

Answer:

The answer is option A

Step-by-step explanation:

The rule for the sequence is

$A(n) = 5. {2}^{x - 1}$

where x is the number of terms

For the first term

x = 1

That's

$A(1) = 5. {2}^{1 - 1}$

$A(1) = 5. {2}^{0}$

A(1) = 5(1)

A(1) = 5

For the fourth term

x = 4

$A(4) = 5. {2}^{4 - 1}$

$A(4) = 5. {2}^{3}$

A(4) = 5(8)

A(4) = 40

For the eighth term

x = 8

$A(8) = 5. {2}^{8 - 1}$

$A(8 ) = 5. {2}^{7}$

A(8) = 5(128)

A(8) = 640

Hope this helps you