The above is the continuation of the thread at How an underdetermined system of linear equations are solved by CVX? - #7 by Mark_L_Stone .
Perhaps you can show a complete MATLAB/CVX code, which makes sense, and which includes all input data (use small matrices, such as 3 by 3 or 4 by 4).
The first thing you need to do is to understand the optimization problem you are solving, and given the input data, why it is a convex optimization problem.
General advice: