- 1- tão = so. She is so fat! - ela é tão gorda!
- 2- tão = as + adjetive (comparison) she is as beautiful as my sister = ela é tão bonita quanto minha irmã,
- 3- tanto =so much / as much ...as (tanto...quanto) there is so much noise (tem tanto barulho!) it has as much noise as my old apartment = tem tanto barulho quanto meu velho apartamento.
- 4- as/like = como (comparison) - i want to find someone like you = quero encontrar alguém como você. She works as a teacher = ela trabalha como professora.
That was the same response I put, I don't think it would be wrong because you are just reinforcing the statement. However, there isn't a word in the Portuguese for the word 'just' in this sentence which is why I think it was marked wrong.