Simplifying Digital Logic Equations: Using Karnaugh Maps and 2x2 Method

[theBEAST]

1. Homework Statement and 3. The Attempt at a Solution
Simplify the equation in the following picture using karnaugh.

http://i.imgur.com/1T2HKpF.jpg

I divided it into two cases, one I used the square and the other I used the 2x1. Will either method work to get the solution, or is the 2x2 better since it is more simplified?

Let's say I wanted to simplify the case 2 solution to get case 1 without karnaugh, how would I got about doing this?

 

[ehild]

You can simplify the case 2 solution, using that $C+\overline{C}B=C+B$

ehild