Well I try to do it by itself offline.
I try to follow your advice. It’s about this project I don’t know if you remind it ^^ (Question about "CRUD with Google Sheets, Web App and AI2")
But if you think it’s not possible, I can consider to do it online, if it’s the only way.
The solver used on the sheet has three variables and the equation of the “target cell” use one of these variables.