1. the formula for the slope is

where (a,0) is x1, y1 and (0,2a) is x2, y2. try to see if you can do it now (:
2. take a number x, then step by step do whatever the question asks for example "First, 3 is subtracted from x" so you know the first thing you need to do is x-3, then go on and you'll get an equation which you can use to solve for x, try it!
3. make a set, S, which has multiples of 7. then make a set, T, which has multiples of 13.
now the intersection of S and T is a set having all elements of S, also found in T (basically the numbers that are common to both). try doing it now!
for fourth, this requires a profit formula(that I do not know), must be explained in your book, try going over it, I'm sure you'll find it there!
Answer:

Step-by-step explanation:
Given:

Required:
Solve for y (make y the subject of the formula)
SOLUTION:

Square both sides


Subtract both sides by x

Divide both sides by 2

M is your answer, because the tangent intersects the circle at point M.
So M is correct.
Answer: Choice C)
--------------------------------------
mean = xbar = (2400+1750+1900+2500+2250+2100)/6
mean = 2150
Subtract the data values from the mean to get
2400-2150 = 250
1750-2150 = -400
1900-2150 = -250
2500-2150 = 350
2250-2150 = 100
2100-2150 = -50
The differences are: 250, -400, -250, 350, 100, -50
Then you square those values and add up the squares
(250)^2 + (-400)^2 + (-250)^2 + (350)^2 + (100)^2 + (-50)^2 = 420,000
C.(x-2)^2+(y+10)^2=9, plug the numbers in the original formula.