When I use TeXmath to add a formula, it puts the same wrong one, no matter what I have typed in.

I am writing some maths notes in Writer, using texmath to enter the formulas. I can’t uninstall TexMath so that I can start again.

it puts the same wrong one

How is the title of your question related to uninstall problem. And what is “the same wrong one”. I’m not a native speaker but I do miss some explanation like *same wrong one as xxxx does" and I don’t find any explanation how you want it to look like, how it looks and which layout commands you use.

And why can’t you uninstall? Any error message, lack of “how - to” knowledge ?

In addition all the usual information from Help -> About LibreOffice is missing. Please edit to enhance the details of your question (Don’t use Add Answer)