The location of point Y is the point -3 on the number line
Here, we want to find the location of Y
let us say the point 0 represents the origin
The coordinates of point x will be (-9,0) while the coordinates of point z will be (3,0)
To find the location of Y , we proceed to use the midpoint formula as follows;

Thus, we have;
(-9 + 3)/2 , (0 + 0)/2
= -6/2 , 0
= (-3 , 0)
Answer: A. divided the difference of the two quantities by the sum of the two quantities.
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Explanation:
The difference of the quantities is 20-15 = 5
The sum of the quantities is 20+15 = 35
Dividing those results leads to 5/35 = 0.142857 which rounds to 0.1429
That converts to 14.29%
This is likely the path Adam took. This path is incorrect. The correct steps are shown below
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Difference = 20-15 = 5
Divide the difference over the original quantity
5/20 = 1/4 = 0.25 = 25%
We have a 25% decrease because the new quantity (15) is smaller than the old quantity (20)
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Here's another way to approach the problem
A = old value = 20
B = new value = 15
C = percent change
C = [ (B-A)/A ] * 100%
C = [ (15-20)/20 ] * 100%
C = (-5/20)*100%
C = -0.25*100%
C = -25%
The negative C value means we have a negative percent change, ie we have a percent decrease. So this is another way to get a 25% decrease.
Step-by-step explanation:
Geometric series.
Month 3.
100(1+\frac{0.02}{12})^2 + 100(1+\frac{0.02}{12})+100
Month 4.
100( 1 + \frac{0.02}{12})^3 + 100( 1 + \frac{0.02}{12})^2+100(1+\frac{0.02}{12})+100
Month 5.
100(1 + \frac{0.02}{12})^4 + 100(1 + \frac{0.02}{12})^3 + 100(1 + \frac{0.02}{12})^2 +100( 1 + \frac{0.02}{12}) + 100