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arcnets
Mar20-03, 04:34 PM
Hi, I'm the guy formerly known as carsten. This is just a test to see if everything works.
OK, you have the numbers
1 2 3 4 5 6 7 8 9 0.
You may insert some + signs and one = sign so to make a valid equation.
Like
12+34+5+6+78=90 (oops, false! [:D])

Happy posting, and a big thanks to Greg who does a great job IMO.
Mulder
Mar20-03, 06:34 PM
Easy[6)] ..
1+2+3+4+5+67+8=90 [:)]
arcnets
Mar21-03, 07:53 AM
Yes. There's more solutions. [;)]
drag
Mar21-03, 12:22 PM
1 + 2 + 3 + 4 + 56 + 7 + 8 + 9 = 90
12 + 3 + 45 + 6 + 7 + 8 + 9 = 90
[t)]
Njorl
Mar21-03, 01:30 PM
You used the 9's twice drag.

12+3+4+56+7+8=90
1+23+45+6+7+8=90
nothing =890
nothing=7890
etc.

Njorl
Njorl
Mar21-03, 01:34 PM
If 2n-1 is prime, what can you say about (2n-1)*(2n-1)?

Njorl
Ben-CS
Mar21-03, 02:06 PM
Perfect!
Njorl
Mar21-03, 03:14 PM
Absolutely. I thought that would take longer.

Njorl
climbhi
Mar23-03, 07:55 PM
Originally posted by Ben-CS
Perfect!
What do you mean perfect?
Njorl
Mar24-03, 03:59 PM
A perfect number is equal to the sum of its factors. For this purpose, 1 is considered a factor, but the number itself is not.

Factors of 6 are 1,2,3 1+2+3=6
Factors of 28 are 1,2,4,7,14 1+2+4+7+14=28

6 and 28 are perfect.

Njorl