How exactly doea encryption and factory resets work

A

AC Question

I'm about sell my phone so the other day I did a factory reset. However is discovered recently that for a factory reset to be fully effective it is better to encrypt your data before hand. My two questions are :

1) if I encrypt my phone now and do a factory reset, will it cover any data that I did with the factory reset before

2) I know nothing can never be fully deleted without military hardware, but how effected is an encrypted factory reset. What are the chances someone could recover photos, text messages, account information, internet history, baking records, etc.

Thanks for the help