B and C are absurd; if a series converges, it must have a sum, but if a series diverges, it cannot have a sum.
Now, notice that

That is, we can write the sum more compactly as

The series is geometric with common ratio

, so the series converges (and thereby has a sum), so the answer is D.
Answer:
it took 60 minutes to fill up 800 gallons of water???
Answer:
- increasing: (-∞, 0)
- decreasing: (0, ∞)
Step-by-step explanation:
The function goes up to the right until it gets to the vertex at x=0. Then it goes down to the right. That is, it is ...
increasing from -∞ to 0 (not including 0)
decreasing from 0 to +∞ (not including 0)
_____
At x=0, the function is neither increasing nor decreasing, so x=0 is not part of either interval.
Answer:
2
Step-by-step explanation:
Since x=-2
-2+3y=4
Add 2 on both sides
3y=6
Divide 3 on both sides
y=2
#8: $900. (I found this answer by multiplying 3000 and 0.3 by the way)
#9: 160 miles. I found this answer by multiplying 80 by two, since two halves/50% make a whole or 100%.