Answer:
Infinite series equals 4/5
Step-by-step explanation:
Notice that the series can be written as a combination of two geometric series, that can be found independently:

The first one:
is a geometric sequence of first term (
) "1" and common ratio (r) "
", so since the common ratio is smaller than one, we can find an answer for the infinite addition of its terms, given by: 
The second one:
is a geometric sequence of first term "1", and common ratio (r) "
". Again, since the common ratio is smaller than one, we can find its infinite sum:

now we simply combine the results making sure we do the indicated difference: Infinite total sum= 
Answer: C
since the line isn't straight, the slope/function is decreasing but not at a constant rate

As

, the sequence

converges to zero.
If you're talking about the infinite series

well we've shown by comparison that this series must also converge because we know any geometric series

will converge as long as

.
I think is
4x - 3 (-2) = 18
4x + 6 = 18
4x = 12
x = 3