What is the correct result?

[dm319]

1 ÷ 2a (or 1÷2a) will always mean 1÷(2 x a) for me.

BODMAS/PEMDAS is just a helpful acronym to help school children. I don't know when it attained the rank of an international standard.

There is no such thing as implicit multiplication or juxtaposition. There are just 'terms', 'products' or 'distributive law', of which contain coefficients or factors. New terminology is not needed.

There isn't ambiguity - once you've identifed that something is a term, it is clear how the expression is calculated. People claiming ambiguity are being deliberately obtuse because they don't want to accept they're doing it wrong.

There is plenty or historical mathematical context and modern school textbooks that support this concept, but not the reverse.