Have they found fossilized bacteria on Mars or not?A textbook i read said that, and now another says no support of simple or complex life has been...

The most up to date information that I know of is that
NASA says that they have not found any actual evidence of life on
Mars.

I do not know what any of your textbooks might say,
but the one that says there was life may be based on a 1996 announcement in which some
NASA scientists showed a rock that they said had holes and stuff in it showing a colony
of bacteria had lived there.  But since then, that interpretation has been discredited
and is not widely believed.

So, as you can see if you look
at the link, current thinking is that there is no evidence of life on Mars at this
point.  I wonder if the text that said there was life is older and the one that says
there was not is newer.