You don't know? Noone does
Modern slot machines are more like watching a movie than watching for three 777's. They look complicated, and its always fun to watch first-timers stand, baffled, pouring over their decision to press 'start' and then walking away after gambling one Cent. Don't worry. Obviously, you're likely to lose, but once you accept that, sit back and enjoy the moments when you're up. (In Vegas, leaving 'broke even' is winning).
The Method
Anyone who says they have a method for winning, is wrong, lying, or insane. however, a method to lose less is key...
Bet your one cent and wait for the cocktail waitress to come round. After a few cents, order a free drink, you can drink all week 'for free' (tip the waitress a dollar, and bet low, and you're basically spending less than 2 dollars a drink.
Take your budget
You have a safe in the room. Trust us. Leave it. Leave your money in there, apart from what you want to spend.