If I take the GRE exam twice and score LOWER on the second test; which
of the two scores will be reported to the schools I apply to?

Hello.

From the GRE web site:

"Cumulative Reporting
GRE score reporting is cumulative. Current GRE Board policy states
that your scores are reportable for 5 years. Your scores are retained
for the 5 testing years following the testing year in which you
tested. All scores earned during this time will be reported to each
institution you designate. You may choose to send only General Test
scores, only Subject Test scores, only Writing Assessment scores, or
any combination of the above, but you may not choose to have only
those scores from a specific test date reported."
http://www.gre.org/getscore.html#cumulative

In other words, any score reports that are sent out after you take the
second test will include your scores from both the first test and the
second test regardless of whether your scores went up or down.

search strategy: gre, "score reports"

I hope this helps.  Good luck with the test!

thanks.