Just a simple question I want to know how to do, google hasn't been a help.
Show that A + 0 = A
Is it something like, make A a 1 so its 1 + 0 = 1?
Is A a matrix? If so, are you working over arbitrary field, over reals...?
Nevertheless, to verify this for matrices you just have to look at each position, you get equality, which is valid in any field (in particular, in reals).
However, it was just a guest that you mean matrices - you should have specified the context of your question.

