Your answer is going to be letter D.)?
Let's start from what we know.

Note that:

(sign of last term will be + when n is even and - when n is odd).
Sum is finite so we can split it into two sums, first

with only positive trems (squares of even numbers) and second

with negative (squares of odd numbers). So:

And now the proof.
1) n is even.
In this case, both

and

have

terms. For example if n=8 then:

Generally, there will be:

Now, calculate our sum:



So in this case we prove, that:

2) n is odd.
Here,

has more terms than

. For example if n=7 then:

So there is

terms in

,

terms in

and:

Now, we can calculate our sum:




We consider all possible n so we prove that:
Answer:
Average distance traveled in 15 minutes = 7.5 miles
Step-by-step explanation:
Given function:

where
represents average distance traveled in miles and
represents time in minutes traveled.
To find the average distance traveled in
minutes.
Solution:
In order to find the distance traveled in 15 minutes, we will input
in the given function.


miles
Average distance traveled in 15 minutes = 7.5 miles
Answer: x(.25)+(4+x(.25))=y
Step-by-step explanation:
1. set up the equation-
Ali has an unknown amount of quarters so make that x.
We know quarters are 25 cents so .25 if he has one quarter you put that one quarter into x, 2 into x and so on
Tom has 4 more, since he has 4 more it is 4+x and one again times .25
2. that is it