Which of the following represents the general equation for the geometric sequence? -1, -2, -4, an = 1 · 2n - 1 an = -2n - 1 an = 2n - 1 an = 1 · 2n + 1

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Step-by-step explanation:

Given : geometric sequence  -1, -2, -4, ...

To find : Which of the following represents the general equation for the geometric sequence.

Solution : We have given

Geometric sequence  -1, -2, -4, ...

By the formula for general equation : .

Where,   = last term.

=  first term.

r = common ratio.

r ( common ratio ) = .

In  -1, -2, -4, ...

= -1.

r ( common ratio ) = .

r ( common ratio ) =2.

Plug the values in formula

.

.

Therefore,  .

question is incomplete.