I wrote a (very long) blog post about those viral math problems and am looking for feedback, especially from people who are not convinced that the problem is ambiguous.
It's about a 30min read so thank you in advance if you really take the time to read it, but I think it's worth it if you joined such discussions in the past, but I'm probably biased because I wrote it :)
If there are rules about which dot comes first then you are not allowed to do this.
You aren't allowed to do this because division isn't transitive.
In fact you're not allowed to add the multiplication - it breaks up the factorised term, hence gives a different answer.
The rule is you're not allowed to add dots (multiplication) - broke up the factorised term, which is why a different answer.