What is the sum of the first seven terms of the geometric series 2 − 8 + 32 − . . ?
hint: cap s sub n equals start fraction a sub one left parenthesis one minus r to the power of n end power right parenthesis over one minus r end fraction comma r ≠ 1, where a1 is the first term and r is the common ratio.
s7 = 6,554
s7 = −8,192
s7 = 8,192
s7 = 10,922

Step-by-step explanation:

The given series is

The first term of the sequence is

There is a common ratio of

The sum of the first n terms of a geometric sequence is given by the formula;

We want to find the first seven terms so

We substitute the given values into the formula to obtain;

The correct answer is A

step-by-step explanation:

you divide the denominator by the numerator on both sides and if the quotients are equal then the fractions are equivalent