Dear, there is no solution to this equation 
 
        
             
        
        
        
Answer: Choice A) M = 0.25n + 100
=============================================================
Explanation:
For now, I'll treat n as x, and M as y.
In other words,
- x = number of CDs
- y = total mass in kg
Let's select two points from this graph. I'll pick (200,150) and (400,200)
The slope of the line through those points is
m = (y2-y1)/(x2-x1)
m = (200-150)/(400-200)
m = 50/200
m = 0.25
Now we'll use the point (x,y) = (200,150) along with that slope value to find the y intercept b
y = mx+b
150 = 0.25*200+b
150 = 50+b
150-50 = b
100 = b
b = 100
You could also use (x,y) = (400,200) and you should get the same b value.
In fact, any other point from this graph works as well.
------------------------------
Since m = 0.25 and b = 100, we go from y = mx+b to y = 0.25x+100
This then translates over to M = 0.25n + 100 which is choice A
To help verify this, let's say we plugged in n = 100
M = 0.25*n + 100
M = 0.25*100 + 100
M = 25 + 100
M = 125
Which is confirmed by what the graph shows. I'll let you check the other points as well.
 
        
             
        
        
        
Answer:
B) 42:28
Step-by-step explanation:
First, let's get 12:18 simplified to make it easier to compare:
12:18 -> 4:6 - > <u>2:3</u>
Now let's check it against all the options:
A) 20:30 -> 2:3 and 2:3 = 2:3 
Not our answer as it is congruent (equal too, the same as, etc)
B) We can see that the first number is larger than the second number, so without doing too much math we can see this is our answer!
 42:28
(it simplifes to 6:4 -> 3:2)
(we do not have to do the following as we already have an answer, but here is the math)
C) 4:6
4:6 ->
2:3 = 2:3
D) 2:3
2:3 = 2:3
 
        
             
        
        
        
The answer would be each pair of sandals costed $14
$14+$14=28+$3=$31
        
             
        
        
        
Y=mx+b
m=slope
b=y itnercept
remember the points go in (x,y) form
also, an easy way to find points is to subsitute values for x andn get values for y 
so 
6. y=5x-1
 some points are (0,-1) (1,4) (2,9) (314)
7. y=-x+8 
some points are (0,8) (1,7) (2,6) (3,5)
8. y=0.2x+.3
somepoints are (0,0.3) (1,0.5) (2,0.7) (3,0.9)
9. y=1.5x-3
somepoints are (0,-3) (1,-1.5) (2,0) (3,1.5)
10. y=-1/2x+4
somepoints are (0,4) (1,7/2) (2,3) (3,5/2)
11. y=2/3x-5
some points are (0,-5) (1,-13/3) (2,-11/3) (3,-3)