Math Question - Solve for c? :)

I need a little help solving a math problem. I'm quite good at math, but I fail terribly in knowing which order I need to move the variables in this type of equation:
http://flic.kr/p/cn2YTq

I don't really care what the answer is, I just want to know how to get it. (What's the point of an answer, with no way of knowing how you came by it?)

Thank you!

Get a common denominator for the 2. So you have to multiply it by c, since it's on the side that says (1/c)

So 2 = 2c / c.

So then the right side becomes (1 - 2c)/c.

Then, just do a proportion.

a/b = (1 - 2c)/c

b(1 - 2c) = ac

b - 2bc = ac

b = 2bc + ac

Factor out the c

b = c(2b + a)

Divide by 2b + a

b/(2b + a) = c

I hope this information was very helpful.

Hey, look here!

To remedy the problem (which it did not seem to be) with ajedrez's method, I simply multiplied for a common denominator across the board. bc(a/b)=bc((1/c) - 2) --> ac = bc - 2bc. Same answer, slightly different way.

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a/b=(1/c)-2---add 2 to both sides
(a/b)+2=1/c---multiply both sides by c and divide both sides by [(a/b)+2)] to isolate c
c=1/[(a/b)+2]

Basically just isolate the variable you're looking for, in this case c. Good luck.