Sum is unique?

1. Jun 11, 2006

Mollet1955

if u have 3 primes: x,y,z
then prove its sum m=x+y+z is unique ? Thank you

2. Jun 11, 2006

matt grime

As stated it is a none question: given any three numbers there is a unique number that is their sum.

3. Jun 11, 2006

Mollet1955

Oh I stated probme incorectly,
let x,y,z be primes, m=x+y+z
Can u find other three primes that can sum to get m ? m can be any number.

4. Jun 11, 2006

matt grime

Of course you can. You should try it. It's possible to find infinitely many counter examples, and there is a number less than 20 that is the sum of two primes in two different ways.

5. Jun 11, 2006

Tide

Yes, but the question concerns three primes!

6. Jun 11, 2006

shmoe

So add the same prime to both pairs.

7. Jun 12, 2006

Tide

Of course. Nevermind!

8. Jun 21, 2006

ramsey2879

I think that by other you have to find three totally different primes.

This too is easy 3+13+31 = 7+11+29. Again, using 3 and 7, and two sets of twin primes. there are infinitely many examples assuming that their are infinitely many pairs of twin primes.

9. Jun 22, 2006

Mollet1955

If so, I think I can't go on solvin this problme
Clearly a simple sum repeated day after day, trying to complicate the main porblme :rofl: