Answer:
Equation C: 5/8x + 2..5 = 3/8x + 1.5 + 1/4x
Step-by-step explanation:
Let us go through each of the equations one by one.
Equation A: 
This simplifies to

which has infinitely many solutions.
Equation B: 
this simplifies to


which is exactly one solution.
Equation C: 
this simplifies to


There's no way this is going to be possible; this equation has no solutions.
Equation D: 
this gives


which is exactly one solution.
Thus we see that it is equation C that has no solutions.
Anything raised to the 0 power = 1
Answer:
The second choice is the same so it is the last one
The answer to your question is 13<2/3
An alternating series

converges if

is monotonic and

as

. Here

.
Let

. Then

, which is positive for all

, so

is monotonically increasing for

. This would mean

must be a monotonically decreasing sequence over the same interval, and so must

.
Because

is monotonically increasing, but will still always be positive, it follows that

as

.
So,

converges.