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