I can prove that 7 x 13 equals 28, you say no it does not, 7 x 13 = 91. I say no, it is 28.

Only a Math Magician can prove that 7 x 13 is 28, Here is how.

7 x 1 = 7
3 x 7 = 21
21+7=28

So therefore 7x13=28




There is another way to do it


7 does not divide into 2 but it does divide into 8 at one time. so if 8 divide by 2 is 4 then 2 x 4 = 8, so 7 divide into 8 once, leaving 1, 2 and 1 is 21, so 21 divide by 3 is 7. Therefore that makes 7 x 13 = 28.


Try this with people, if you talk fast enough, you can fool your audiences.

Hmmm, not the audiences I talk to. They would look at me like I was out of my mind.

Bruce

7 X 13 also means:

13
+13
+13
+13
+13
+13
+13
_____

Then total from the bottom up, 3+3+3...which is 21, then total the 1's and the total is 28 too.

PSIncerely Yours,
Paul Alberstat

I forgot about that too Thoughreader.

It won't go pass my friends. they are mathematicians.

Hmm
7*13 is 29 in base 41.
And it is 28 in base 41.5.

But.. do bases like 41.5 exist?

Now we can prove that 2 = 1 and that all horses are white...
:pepper:

Wow.. I thought I'm the only one like that *g*
Know that one?

lim sqrt(3) = 2
3->4

I want to print it on a t-shirt

Abbott & Costello at their best.
Greg

Thats easy!

let x=y so that x-y=0

=> 2(x-y)=0

=>(x-y)=2(x-y)

Dividing both sides by (x-y) gives 1=2 as required.

QED etc etc

Okay, does that allow you to prove 1=3, or in general n=m ?

It does. 3(x-y)=(x-y) and divide by (x-y).

Of course, there is a very good reason why all of this couldn't be more wrong...

I can prove that:

14/7[4+17(6-3)]+20 = 130

I'll just let that sink in for a little bit...




:)

The question is "why?"

We all got the joke when the premise was stated:
"let x=y so that x-y=0 "

In this case, post hoc ergo proctor hoc applies.

I hope most of the posters understand that the notion of proof used in this thread is more aptly translated into common English as 'convince' or 'demonstrate'.

There are people who use words like theorem, theory, hypothesis and proof in a less forgiving context.

Bill,
Most of us here are being math geeks for the sake of math geekiness. There is little to no magic here - by intent.

And I would hope most of us are bantering about a well-known falacious proof, the sort of thing one puts in front of a high school algebra class and asks them to find the mistake. At least that's what I meant when I brought up the 2 = 1 "proof," as well as the "all horses are white," for which I see there are no takers.
:banana:

Sqrt(1/-64 pizza) = I over-ate pizza!!!


Work on that one

Use the calculator

Obviously the 2=1 proof cannot be correct.

For anyone who did not pick up on the discrepancy, first it was stated that x - y = 0.

Therefore, in the next to last step, dividing both sides by (x - y) cannot be possible, because you cannot divide by 0.

I was just wondering what this has to do with magic...

Rgranville writes:

Okay here we go:

"All horses are white" is logically equivalent to "No non-white objects are horses"; therefore every non-white object that is not a horse is confirmation that "All horses are white." Well, since I can point to an infinite number of non-white non-horse objects, I have an infinite number of confirmations that all horses are white.

Now suppose I point to all red non-horse objects, which are also presumably infinite in number. Now since red objects are non-white, then pointing to red non-horse objects confirms, as above, that all horses are white. But red objects are also non-black, so by the same argument above, pointing to red--that is, non-black--non-horse objects confirms that all horses are black.

Hence, all horses are white, and all horses are black.

Now there's another fine mess you've gotten me into, Stanley.


Jack Shalom