Is the word importantes the same in Brazilian and European Portuguese?

Yes.

The spelling, meaning, and grammatical function of "importantes" are identical in both Brazilian and European Portuguese. The only difference is pronunciation. In Brazilian Portuguese, unstressed vowels tend to be more open and clearly articulated (the final "e" is often pronounced like a short "i"). In European Portuguese, unstressed vowels undergo significant reduction, meaning the final "e" is often "swallowed" or becomes a very short, nearly inaudible sound.

Brazilian Portuguese Examples

1. Estes documentos são muito importantes. (These documents are very important.)
2. Eu tenho várias coisas importantes para fazer hoje. (I have several important things to do today.)
3. Essas mudanças são muito importantes para o projeto. (These changes are very important for the project.)
4. Os resultados foram muito importantes para a nossa equipe. (The results were very important for our team.)
5. Existem avisos importantes no mural da empresa. (There are important notices on the company bulletin board.)

European Portuguese Examples

1. Estes documentos são muito importantes. (These documents are very important.)
2. Tenho várias coisas importantes para fazer hoje. (I have several important things to do today.)
3. Essas alterações são muito importantes para o projeto. (These changes are very important for the project.)
4. Os resultados foram muito importantes para a nossa equipa. (The results were very important for our team.)
5. Há avisos importantes no mural da empresa. (There are important notices on the company bulletin board.)