Here we're discussing the "nth partial sum of a geom series."
1 - r^n
The formula for that is s(n) = a(1) ---------------
1-r
We can subst. the given values and see where that takes us:
1 - (-2)^6 1 - 64
105 = a(1)*---------------- = ----------*a(1) = -21*a(1)
1-(-2) 3
105
Solving this for a(1): a(1) = --------- = -5 (answer)
-21
The answer is 36 (Don't mind the comment, I forget you could edit the answer)
36 / 4 = 9
36 + 4 = 40
40 / 5 = 8
C
She'd have to have given her more than 48 dollars to receive more than 30 dollars back
It can't be D because that implies she could've received exactly 30 dollars in change and the question states she received more than that.
Answer:
53
Step-by-step explanation:
9 + 9 = 18
42 - 18 = 24
24 / 2 = 12
the length is 12 inches
