Find all the zeros of the function f(x)= x^2(x+3)(x^2-1) step by step

A. divided the difference of the two quantities by the sum of the two quantities.

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

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)

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.