I don't know how best to ask this question. If I have a equation with more 
unknowns that knowns and want to know the possible solutions and get 
something like this,

>>> solve(a*x+a+b*y-c-d, a, b)
[(0, (c + d)/y), (c/(x + 1), d/y), (d/(x + 1), c/y), ((c + d)/(x + 1), 0)]

Is there some significance of these 4 solutions? Are these solutions 
analogous to the case of `solve(a + b, a)` giving a = -b? The problem that 
I see is that if you write 

>>> solve(a*x+a+b*y-4, a, b)
[(0, 4/y), (4/(x + 1), 0)]

Those are only 2 of an infinite number of solutions since there are an 
infinite number of ways to partition up the 4. If we partition 4 as c + d 
(which then gives a solution that we obtained above) then substituting in 
different values of c and d gives a variety of solutions:

>>> ans=solve(a*x+a+b*y-c-d,a, b)
>>> [Tuple(*ai).subs({c:1,d:3}) for ai in ans]
[(0, 4/y), (1/(x + 1), 3/y), (3/(x + 1), 1/y), (4/(x + 1), 0)]
>>> [Tuple(*ai).subs({c:2,d:2}) for ai in ans]
[(0, 4/y), (2/(x + 1), 2/y), (2/(x + 1), 2/y), (4/(x + 1), 0)]
>>> [Tuple(*ai).subs({c:4,d:0}) for ai in ans]
[(0, 4/y), (4/(x + 1), 0), (0, 4/y), (4/(x + 1), 0)]

(Solving this type of equation arose in doing the 
multinomial_coefficients-without-expansion problem.)

/c

-- 
You received this message because you are subscribed to the Google Groups 
"sympy" group.
To view this discussion on the web visit 
https://groups.google.com/d/msg/sympy/-/GoH1R94OvUEJ.
To post to this group, send email to sympy@googlegroups.com.
To unsubscribe from this group, send email to 
sympy+unsubscr...@googlegroups.com.
For more options, visit this group at 
http://groups.google.com/group/sympy?hl=en.

Reply via email to