Subject: Re: What the heck?
Date: Sat, 13 Jan 2001 10:33:02 +0100 (MET)
From: Ivan Sovic

If you want a integer solutions, look at this:

1  1   1
--+--=---  /*7xy
x  y   7

7y+7x=xy
7y+7x-xy=0
y(7-x)+7x=0
y(x-7)=7x
   7x

y=----
  x-7
   7x-49+49

y=----------
    x-7
       49

y=7+ -------
      x-7
                 49
y is integer if ----- is integer.
                 x-7


That is integer if x= -42, 0, 6, 8, 14 or 56.

                              1   1
It can't be 0, because then  ---=---
                              y   0
is imposible.

Solutions are (56,8), (14,14), (8,56), (-42,6), (6,-42).

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