Re: Diophantic Equations with Constraints
- To: mathgroup at smc.vnet.net
- Subject: [mg49495] Re: Diophantic Equations with Constraints
- From: "Dana DeLouis" <delouis at bellsouth.net>
- Date: Thu, 22 Jul 2004 02:45:06 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Just a quick and dirty way to test if there is a possibility of a solution
(maybe not integer) might be something like this. The solution is in the
range of 0-47, so we can quickly see that with 148, there are no solutions.
However, 14 is in the range, so there is a "chance" there might be integer
solutions.
In[1]:=
3*x + 2*y - z /.
{x -> Interval[{3, 8}],
y -> Interval[{0, 12}],
z -> Interval[{1, 9}]}
Out[1]=
Interval[{0, 47}]
In[2]:=
FindInstance[
{3*x + 2*y - z == 14,
3 <= x <= 8,
0 <= y <= 12,
1 <= z <= 9},
{x, y, z}, Integers, 100]