Formula linking to another table checkbox

I’m trying to create a formula that I don’t think should be too complex but I can’t seem to figure it out.

I have an Agenda table with a list of agenda items, and a To Do column that links to a To Do table.

In the To Do table, team members can check off it that thing has been done or not.

I would like to write a formula in the Agenda tab that will essentially remove the To Do items once they have been checked off.

I’m fine with creating a new To Do column and hiding the original one if that’s necessary, but I can’t seem to figure this out.

Any help would be appreciated!

A very similar question was asked not long ago. Here’s the thread, where you can find my response. Will this work for your scenario?