decoder & multiplexer

[david90]

Is there a systematic ways of expressing a boolean equation such as "ab+a'c" using multiplexer? Eyeballing and trial and error do not seem to work [:D] .
What about decoder? Will k-map help?

I have to design a 4 to 16 decoder using 2 to 4 decoder with some gates. I also have to design a full subtractor using decoder. How can u do it systematically (step by step)?

Thanks![:)]

[Nice coder]

Sorry but we are not meant to do homework questions [:(]

[david90]

Just give me an example.

[Hurkyl]

I bet your textbook has examples! It might even have done a problem just like the one you ask (but with different sizes)!