using k-mapping: simplify and create truth table

1. (wx'+y')'+x'y'
2. (ab')'+((c)')'+a'b'c'
3. x'yz'+x'yz+xyz'+x

[Walter Roberson]

How does this differ from your earlier question http://www.mathworks.com/matlabcentral/answers/301312-boolean-algebra-simplify-and-truth-table ?