Hello everybody, Anybody know plumbing?

Reason I ask this, is because both the bathroom sink, and the tubs drains are going slowly. They've both been going slower and slower, and they've been ignored untill now. Both had lots of drano down them, to no avail. I took apart the sinks plumbing (to the p trap), and cleaned a bunch of gunk out of it, but its still slow. I'm dumbfounded as to what I should do to the tub, because doing the plastic fitting on the sink was a pita, cant imagion what the metal piping is like...

Can somebody help me? I really dont know alot about plumbing, but If somebody teaches me I can learn.

I hope to tackel it this weekend if its not major

Thanks alot
~Nate

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1999 Plymouth Neon Expresso. 2.4 swap, 10.5 to 1 comp, big cams. Autocross time attack vehicle!
2012 Escape, 'hunter" (5 sp 4cyl)