<u>Understanding:</u>
The sum of a geometric series is, 
, with a being the start point and r is the common ratio. We can also use the following formula to make life easier 
, a is your start point, r is the common ratio, and n is the number of terms, which in our case is S7.
<u>Solution:</u>
Our start point is 1, 
,
The common ratio is 5, 
,
And finally, the number of terms is 7, 
.
The answer is [A] 19531.
Answer:
5a²+22a+8
Step-by-step explanation:
(5a×a)+(5a×4)+(2×a)+(2×4)
=5a²+20a+2a+8
=5a²+22a+8
Answer:
8
Step-by-step explanation:
2^3 is the same as 2 x 2 x 2
2 x 2 is 4 and 4 x 2 is 8
so 2^3 is 8
