Why is (100*.25)-100) difrint then 100/1.25 should'nt it be the same?

Question

If 25% of 100 is 75 then why cant i devide 100 by 1.25 and get the same number

Answer 1

100 * 0.25 - 100

= 100 * 0.25 - 100 * 1

= 100 * (0.25 - 1)

= 100 * ( -0.75) = -75

Notice how the distributive law gives us the 0.25 - 1, which is a negative quantity. What you want to do that is equivalent is actually not dividing but multiplying, and you should use the quantity:

0.25 - 1

NOT the quantity:

0.25 + 1

Division by 1.25 is not the same as multiplication by -0.75. If you wanted something to divide by, you'd just use:

1 / (-0.75) = -4/3

Watch: 100 / (-4/3) = -300/4 = -75.

See?

Answer 2

100 * 0.25 = 25 so the first equation equals 25 - 100 = -75

The second equation equals 100 * 4/5 = 80

25% of 100 is 25. This is not the same as dividing by 1.25. It is the same as dividing by 4.

I think you have a misunderstanding of percents and fractions and how they relate. Taking a percentage of something (e.g. 25%) is the same as multiplying by the decimal equivalent of the percent (in this case, 0.25).

Answer 3

100*.25 - 100 ->
25 - 100 ->
-75.

100/1.25 = 80.

The reason they aren't the same can be seen by factoring the 100 out of the first eqn:
100(.25-1)
100(-.75)

Multiplying by -.75 is the same as dividing by 1.3333...., not by 1.25.

Answer 4

Work them out:

100 * .25 = 25
25 - 100 = -75

100 / 1.25 = 100 / (5/4) = 100 * (4/5) = 80

Your first assumtion is incorrect. 25% of 100 is 25.