Monitors show the value of the Facebook, Inc. stock during morning trading at the NASDAQ Marketsite in New York in this file photo taken June 4, 2012. Credit: Reuters/Eric Thayer/Files By Alexei Oreskovic SAN FRANCISCO | Thu Jul 26, 2012 5:37pm EDT (Reuters) - Facebook Inc reported a drastic slowdown in revenue growth and failed to offer financial forecasts to quell fears about its ability to boost advertising growth, sending its shares plummeting to a record low. In its inaugural earnings report since becoming the first American company to debut with a value of more than $100 billion,…