In the first time I recommend you to use it (rewrite the problem with '+' signs), but as you proceed you should try to solve the problems without it. I show you examples here for both ways. NOTE: Signed numbers should always be in parantheses. As a general rule, we can never write two signes next to each other: Instead of 5 + -3 you should write: 5 + (- 3).
The Watergate Scandal refers to a series of events that occured between 1972 and 1974. The scandal got its name from the burglary at the headquarters of the Democratic National Committee in the Watergate Hotel Complex in Washington, D.C. Evidence found on one of the burglars implied a possible link to the White House and prompted an investigation. Over the next two years, the political links were found to reach increasingly higher up the power chain.
July 27 - Thirty years after the Senate select committee hearings on Watergate riveted the nation and doomed the Nixon presidency, a key figure in the scandal says he has a fresh and explosive revelation: Richard M. Nixon personally ordered the burglary of Democratic headquarters at the Watergate complex.