Language / How similar are Polish and Romanian languages? [75]

I live in Serbia, Beograd, and I travel quite often to Romania, travelled it from the Danube till the Black Sea.
I can tell you one thing, oldest letter of Romanian language was written in Serbian language, still being kept in Romanian archives.
Romanians used to speak Serbian language until 150 years ago, it's not Polish, it's Serbian, those Serbian words were replaced
by the French-Italian-Latin words.
Even the genetic map putts Serbs, Romanians close, and our nations are being considered as brother nations, we never went
to war against each others in our whole history.