Question

what is the sum of a 7-term geometric series if the first term is -6, the last term is -24,576, and the common ratio is 4

Answer 1

sum of a geometric series=\[S_n=\frac{ a(r^n+1) }{ r-1 }\]

Answer 2

what is a and what is n

Answer 3

a=1st term, n= term number

Answer 4

and its
\(\large S_n=\frac{ a(r^n-1) }{ r-1 }\)

Answer 5

here, n=7, a=-6,r=4
just plug in values!