Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a set of equations which I would like to symbolically solve for a defined set of variables using the solve command in Maple. However, being not familiar with the program, it does not give me exactly what I would like. Maybe someone can give me a hing. Here's a simple example to illustrate my issue:

Given the system of equations \begin{align} x+b &=2\cdot y + y - a\\ y-a &= b, \end{align} using the solve(...,{x,y}) command in Maple gives me the result \begin{align} y &=a+b\\ x &= 2\cdot b + 2\cdot a. \end{align} What would be sufficient for me is to have one of the variables to be solved for as a function of the second one, i. e. \begin{align} y &=a+b\\ x &= 2\cdot y. \end{align} How can I do this?

share|cite|improve this question
I would have expected the second set of results; more or less, what you've told Maple is "solve for $x$ and $y$", and all Maple did was to express $x$ and $y$ in terms of all the other variables you did not indicate in solve()'s second argument... – J. M. Oct 11 '11 at 12:12
Thanks for you comment J.M. I agree with you that one would expect the second set of result posted above. But what can I do in maple to get a representaton of the results as listed at the very end of the posted question? – phj Oct 11 '11 at 13:24

If you're looking for a solution where the value of $x$ doesn't involve $a$, you can solve for $a$ and $x$ in terms of $b$ and $y$:

solve(..., [a,x]);

$$[[a = y-b, x = 2 y]]$$

and then rewrite the first equation to give $y$ in terms of $a$ and $b$:


share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.