The terms of the geometric sequence are 1,3,9, ...,
The first term is a = 1
The common ratio is r = 3.
The sum of the first 10 terms is
Answer: 29524
Not a 100% positive but I believe that your answer would be C.
An=A1+(n-1)d
-20=A1+(15-1)x-7
-20=A1+14 x -7
-20=A1-98
+98 +98
-98+98=0
-20+98=78
A1=78
