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Posted: 11/1/2004 12:56:16 PM EST
[Last Edit: 11/1/2004 3:21:02 PM EST by Marksman762]
I could use a little help with the following problem:
We have to prove that 12, 13, 21, and 31 are the only double-digit numbers whose squares are the reverses of the squares of the reverses of double-digit numbers, specifically the aforementioned numbers. Both show why it works for these numbers, and that only these numbers work this way.
Anyone have an idea?
Thanks
Link Posted: 11/1/2004 12:57:50 PM EST
1+1 = 42
Link Posted: 11/1/2004 12:58:19 PM EST
nope
Link Posted: 11/1/2004 1:03:33 PM EST
[Last Edit: 11/1/2004 1:03:49 PM EST by ChrisLe]
Nope. Not here. I can't handle any mathematics that require me to count in excess of the amount of fingers God gave me.
Link Posted: 11/1/2004 2:56:06 PM EST
BUMP!
Link Posted: 11/1/2004 3:02:58 PM EST
Sorry dude, I have to drop my zipper whenever I need to count to 11!
Link Posted: 11/1/2004 3:11:47 PM EST
Start at 10. Do the math. Stop at 99. Have fun!
Link Posted: 11/1/2004 3:14:12 PM EST
You might also want to inquire about any spelling "wizzards" while you're at it... sorry, I just couldn't resist.
Link Posted: 11/1/2004 3:14:48 PM EST
lets see if i can get this right ..223+.308+.50x 1000=
Link Posted: 11/1/2004 3:15:36 PM EST
takes about 2 minutes to solve this in excel...

-luke
Link Posted: 11/1/2004 3:16:02 PM EST

Originally Posted By Marksman762:
I could use a little help with the following problem:
We have to prove that 12, 13, 21, and 31 are the only double-digit numbers whose squares are the reverses of the squares of the reverses of double-digit numbers, specifically the aforementioned numbers. Both show why it works for these numbers, and that only these numbers work this way.
Anyone have an idea?
Thanks



Did you ask Dr Math?

http://mathforum.org/dr.math/

Link Posted: 11/1/2004 3:20:27 PM EST
[Last Edit: 11/1/2004 3:21:25 PM EST by Rem700PSS]

Originally Posted By Marksman762:
I could use a little help with the following problem:
We have to prove that 12, 13, 21, and 31 are the only double-digit numbers whose squares are the reverses of the squares of the reverses of double-digit numbers, specifically the aforementioned numbers. Both show why it works for these numbers, and that only these numbers work this way.
Anyone have an idea?
Thanks



Okay, this is fairly easy.
1. Take 12x12 = 144, 21x21 = 441 (441 = Reverse 144) (21 = reverse 12)
2. Take 13x13 = 169, 31x31 = 961 (31x31, again the reverse)

And so on.

The same works for 21 and 31 as they are only the revereses of 12 and 13, the ones we already did.

IM me if you have trouble understanding.

EDIT: To prove that take two random numbers and do the same operation and show that they are not reversable.
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