- 27 Aug '03 20:14

You are taking the negative root of the expression on the left and the positive root of the expression on the right.*Originally posted by Cheshire Cat***I guess one could probably find this somewhere on the internet; but, can anyone tell me why this is incorrect:**

-20=-20

16-36=-20

25-45=-20

16-36=25-45

16-36+(81/4)=25-45+(81/4)

(4-(9/2))^2=(5-(9/2))^2 (factoring, I think)

4-(9/2)=5-(9/2)

4=5

1=2 (subtracting 3 from each side)

Another example:

(-2)^2 = 4

(2)^2 = 4

(-2)^2 = (2)^2

-2 = 2 - 27 Aug '03 20:17 / 1 edit

I see. Does that mean that the correct answer would be something like 2i=2?*Originally posted by richjohnson***You are taking the negative root of the expression on the left and the positive root of the expression on the right.**

Another example:

(-2)^2 = 4

(2)^2 = 4

(-2)^2 = (2)^2

-2 = 2 - 27 Aug '03 21:14

Hmmm. I'll have to look at that one some more. How about this one:*Originally posted by royalchicken***(4-(9/2))^2=(-0.5)^2**

(5-(9/2))^2=(0.5)^2

As richjohnson said, you can't make the negative and positive roots equivalent.

x=.999999999....repeating 9s

10x=9.999999....repeating 9s

Using systems I think:

~~~~10x=9.999....~~~

~~~~~-x=.9999....~~~

---------------------------

~~~~~9x=9~~~~~~~~

x=1

x=.99999....

1=.999999......

Hope that is understandable. - 27 Aug '03 21:16

That's fine, since 1 = 0.9 rec. There's another thread on this in this forum. Good job, though.*Originally posted by Cheshire Cat***Hmmm. I'll have to look at that one some more. How about this one:**

x=.999999999....repeating 9s

10x=9.999999....repeating 9s

Using systems I think:

~~~~10x=9.999....~~~

~~~~~-x=.9999....~~~

---------------------------

~~~~~9x=9~~~~~~~~

x=1

x=.99999....

1=.999999......

Hope that is understandable. - 27 Aug '03 21:27

They are actually the same number (rec = "recurring".*Originally posted by Cheshire Cat***Why does this work though? Obviously they are two different numbers. And what is your abbreviation rec.?**

Incidentally, the series S=(1/2 + 1/4 + 1/8 + 1/16 + ...) is also equal to one.

Why?

2S=(1 + 1/2 + 1/4 + 1/8 + 1/16 + ...)

2S-S=1 - 28 Aug '03 01:16 / 1 edit
**-20=-20**

16-36=-20

25-45=-20

16-36=25-45

16-36+(81/4)=25-45+(81/4)

(4-(9/2))^2=(5-(9/2))^2 (factoring, I think)

4-(9/2)=5-(9/2)

4=5

1=2 (subtracting 3 from each side)

the first problem works due, as RichJohnson said, because all positive real numbers have two roots both the negative and the positive. Therefore, if you take 2^2 and -2^2 you will get 4 for both. The reason this works is because the eqaution, although, mathematically correct is not balanced correctly. (Or, atleast thats what my maths teacher would say as I messed up a question, in a paper, because I did just this and got the wrong answer)

**Hmmm. I'll have to look at that one some more. How about this one:**

x=.999999999....repeating 9s

10x=9.999999....repeating 9s

Using systems I think:

~~~~10x=9.999....~~~

~~~~~-x=.9999....~~~

---------------------------

~~~~~9x=9~~~~~~~~

x=1

x=.99999....

1=.999999......

Hope that is understandable.

the second was explained to me but I can't for the life of me remember. I'll ask some people and see if they can tell me. - 28 Aug '03 01:31

Cool, thanks.*Originally posted by jimmi t***[b]-20=-20**

16-36=-20

25-45=-20

16-36=25-45

16-36+(81/4)=25-45+(81/4)

(4-(9/2))^2=(5-(9/2))^2 (factoring, I think)

4-(9/2)=5-(9/2)

4=5

1=2 (subtracting 3 from each side)

the first problem works due, as RichJohnson said, because all positive real numbers have two roots both the negative and the positive. Therefore, if you take 2^2 and -2 ...[text shortened]... me but I can't for the life of me remember. I'll ask some people and see if they can tell me.[/b]