First, let's turn all the numbers into improper fractions so that we can find the answer easier.
-2
= r - 
-
= r - 
Now we have to isolate 'r'.
First, we have to make sure that the variable is on one side and all the numbers are on the other side.
To do this, we have to add
to both sides.
In order to do this, we need to ensure that both fractions have a common denominator.
-
= r - 
Ensure that the denominators are the same:
= r - 
+
= r
= r
Good luck!
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:
2
Step-by-step explanation:
2x is the slope which is just 2
Answer:
Aziza’s claim is incomplete. The third side must be between 4 in. and 26 in.
Step-by-step explanation:
With the Triangle Inequality Theorem, saying that the sum of lengths of any two sides of a triangle is greater than the length of the third side. With this we can develop two inequalities:
11 + 15 > x
26 > x
rewrite this as x < 26
11 + x > 15
x > 15 - 11 Subtract 11 from both sides
x > 4
Therefore, the third side can be anywhere greater than 4 inches and less than and less than 26 inches.
4 < x < 26