[BASIC HELP] Equations on HP Prime

[fpicoral]

Hello there!
First, I would like to apologize for such a noob question.
I don't know if this is possible - probably it's but I'm to stupid to find it myself: how can I """de-siplify""" (I really don't know how to properly call this) an equation?
Let's say I have (a+b)^2, where can I put it to see a^2+2ab+b^2?
I know about the Solve app but if I'm right I need to give a value to the variables to solve one of them, e.g set b=3 in (a+b)^2.

Thanks in advance for the help.
If this question still confusing, I can try to explain it better in the comments.