# 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: