Answer:
i think y=3/4x-4.2
Step-by-step explanation:
The first thing we are going to do is find the area of the field. To do this we are going to use the area of a square formula:

Were

is the area in square kilometers

is one of the sides of the square
We know for our problem that the side lengths of the field are 0.9 kilometers, so

. Lets replace that value in our formula to find

:

Now, to find the population density of the filed, we are going to use the population density formula:

where

is the population density in <span>in burrows per square kilometer
</span>

is the number of burrows

is the are of the field
We know that

and

, so lets replace those values in our formula:


We can conclude that the <span>density of prairie dog burrows is approximately
2444 burrws per square kilometer.</span>
Answers:

========================================================
Explanation:

Note we subtract 3 off the previous term (t1) to get the next term (t2). Each new successive term is found this way

and so on. This process may take a while to reach 
There's a shortcut. The nth term of any arithmetic sequence is

We plug in
and simplify

Then we can plug in various positive whole numbers for n to find the corresponding
value. For example, plug in n = 2

which matches with the second term we found earlier. And,

---------------------
The notation
refers to the sum of the first ten terms 
We could use either the long way or the shortcut above to find all
through
. Then add those values up. Or we can take this shortcut below.

The sum of the first ten terms is -85
-----------------------
As a check for
, here are the first ten terms:
- t1 = 5
- t2 = 2
- t3 = -1
- t4 = -4
- t5 = -7
- t6 = -10
- t7 = -13
- t8 = -16
- t9 = -19
- t10 = -22
Then adding said terms gets us...
5 + 2 + (-1) + (-4) + (-7) + (-10) + (-13) + (-16) + (-19) + (-22) = -85
This confirms that
is correct.