This is a problem dealing with permutations and combinations.
Order does not matter in this problem.
Since order doesn't matter, it is a combination.
Repetition matters, since you can't have the same person count as two people.
There are twelve slots.
_ _ _ _ _ _ _ _ _ _ _ _
Each slot needs to be multiplied by the next.
_*_*_*_*_*_*_*_*_*_*_*_
Now we have to fill in the slots.
Each slot will be filled with a number one less than the one before it. It has to be one less, since repetition matters.
The numbers will be decreasing from 30, since there are 30 possible people.
30 * 29 * 28 * 27 * 26 * 25 * 24 * 23 * 22 * 21 * 20 * 19
Multiply these numbers together and you get your answer.
41,430,393,164,160,000 ways
Slope is

Then you use the equation

Where b is the y-intercept. To find it, plug in x and y from one of the points. Say, point 1 (1,10):

You know m (from above) and now you can solve for b.
Rearrange terms:

And that will be the answer.
Make sense?
Answer:
Step-by-step explanation:
We assume you want to compare your expression to the form ...
a(x -h)² +k
1/2(x +1)² +k
The multiplier outside parentheses is ...
a = 1/2
The horizontal offset inside parentheses is ...
-h = 1
h = -1
The vertical offset outside parentheses is ...
k = -3
I'm assuming you mean

Write the 2 as a fraction 2/1 and multiply.