## anonymous 4 years ago What's the percent of change for 18. To 10

1. Hero

I gave you the formula for this.

2. anonymous

Is it 80%

3. Hero

Did you input the values into the formula?

4. anonymous

I think so is it 80

5. Hero

I'm going to go over this one last time

6. Hero

did you delete the previous question?

7. slaaibak

${{new - old} \over old} * 100$

8. Hero

The general formula for percent change is as follows: $\% \Delta = \frac{|a-b|}{a} \times100$ where a = original amount, b = new amount In this case, a = 18 , b = 10 Plug the numbers in and solve.

9. anonymous

Ok what do you come up with

10. Hero

you first. I did the last one for you already.

11. Hero

This involves simple arithmetic

12. anonymous

I said it already if it's not 80 then is it 44.4 repeating

13. Hero

Yes, it is 44.4%

14. Hero

It's not 80. Never was, never will be. How you got 80 perplexes me.

15. Hero

No, it stupifies me.

16. anonymous

Ok that's what I though but then the first one you didn't make sense

17. Hero

I posted the same exact formula. Nothing changed.

18. Hero

Don't say what I wrote doesn't make sense. It's not me that isn't making sense.

19. anonymous

So the first answer was 33.3 repeating or 25 as you said

20. Hero

Just 25% not 33 Do you understand what the absolute value symbols mean?

21. Hero

|| means |-x| = x In other words |-5| = 5 So basically, when you evaluate using the absolute value, you drop the negative and use only the positive value. How you're getting two values...I don't know. Don't pay attention to that other guy's formula. It will only confuse you.

22. anonymous

It was 15 to 20 20-15 is 5 5*100 500/15 is 33.3

23. Hero

5/20 = 1/4 = 25% That's the solution to the first one. You're doing some incorrect math there. In the first one, a = 15, b = 20 a = the original amount, b = new amount 15 is the original amount, 20 is the new amount Don't confuse yourself.

24. Hero

You multiply by 100 LAST

25. Hero

You have to divide before multiplying by 100

26. anonymous

Ok I'll just go with your answer and when we check it in class tomorrow I'll just see

27. Hero

Yes, and make sure you get back to me when you find that 25% is the correct answer.

28. anonymous

Oh yea I'll get back to you

29. Hero

Hmm, I just checked my own answer. It really is 33.3%

30. Hero

I take my foot out of my mouth. You are correct

31. Hero

Nevertheless, the formula is correct. Use it.

32. anonymous

Oh I've been using it and I have been getting the correct answers

33. Hero

Great. That's all that matters.

34. anonymous

Btw this made my day it was fun arguing with you thanks

35. Hero

lol

36. Hero

Yeah, I'm not perfect

37. anonymous

Oh yea I know

38. slaaibak

Hero! What rubbish are you posting here? If |-x| = -x IFF x<= 0 Otherwise, |-x| = x if x>=0

39. slaaibak

I'd rather define it as |-x| = -x if x<0 and |-x| = x if x>=0