My tub wont drain what should i do? my bathtub have been draining slower and slower over the month...

my bathtub have been draining slower and slower over the month and today after a roommate took a shower it stopped draining.

i took a plunger to it and hoping it'd generate a difference and it went down somewhat so i integer that there might be a clog since next it has stopped going down and the plunger trick doesn't work anymore.

we really don't enjoy the cash to win a plumber and are kind of incompetent when it comes to house repair. we're a touch worried about chemical drainers because of the pipes are mode of old and don't want to hold to pay for the entire drainage system to be repaired/replaced. any suggestions would be greatly appreciated. Thanks within advanced.
Answers:    With a bath tub you enjoy to go through the over flow (that's the round entry above the drain). Unscrew the two screws and unclog it from near..If you have one of those tub plug lever then you'll hold to take adjectives that off, sometimes that's adjectives you have to do..But if that doesn't work consequently you'll have to use a snake next to a least a 1\4" cable on it to unclog the pipe.
I can't remember what it is call exactly but Lowe's sells a closure strip(?) what it is basically is a plastic strip in the order of 2 feet long near barbs on it, you stick it down the drain and afterwards pull it out and it grab the hair, supposedly. They are a couple bucks at most but they seem to be to work ok. Personally, I would try a liquid drain cleaner (FlowEasy Lowe's also sell this) follow the instructions exactly and it shouldn't hurt the pipes, just look out with the stuff.