# How to solve Couples system of equations in FreeFem++

**URL:** <https://community.freefem.org/t/how-to-solve-couples-system-of-equations-in-freefem/3258>\
**Category:** Feature Request\
**Created:** [May 21, 2024, 3:46pm UTC](https://community.freefem.org/t/how-to-solve-couples-system-of-equations-in-freefem/3258 "2024-05-21T15:46:17Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Monirul25](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.freefem.org/monirul25/32/3287_2.png) [@Monirul25](https://community.freefem.org/u/Monirul25)\
**Post date:** [May 21, 2024, 3:46pm UTC](https://community.freefem.org/t/how-to-solve-couples-system-of-equations-in-freefem/3258/1 "2024-05-21T15:46:17Z")

</div>

Can you please help regarding how to solve couples system of equation in Freefem++ like Cahn-Hilliard equation involving non-linear terms. I have tried but showing error.

---

<div class="post-metadata">

**Author:** ![Liamani](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.freefem.org/liamani/32/2436_2.png) [@Liamani](https://community.freefem.org/u/Liamani)\
**Post date:** [June 11, 2024, 10:43am UTC](https://community.freefem.org/t/how-to-solve-couples-system-of-equations-in-freefem/3258/2 "2024-06-11T10:43:12Z")

</div>

Hello @Monirul25 😊  
As per my knowleadge to solve a coupled system of equations like the Cahn-Hilliard equation involving non-linear terms in FreeFEM++:  
**Here are a some steps and considerations to help you resolve the error.**

- You can Double check the syntax of your FreeFEM++ script for any errors.
- You can Use an appropriate non-linear solver like newton, picard, or broyden.
- Ensure your boundary conditions are correctly defined.
- Verify your initial conditions match the problem setup.
- Review error messages for clues.
- Consult the FreeFEM++ documentation and relevant examples for guidance.

Hope this will help you 😀