4 unknown with 4 equations

Hi everyone, 

I am new to Mathcad and I have 4 unknowns with 4 equations, each equations contains 2 unknowns, therefore all 4 equations are interlinked. See attachment for details. 

My question is: I have used the 'solve' function to solve the equations simultaneously and am expecting the answers in a [4,1] matrix. However, that is not what Mathcad produced. Why is this happening and how should I solve it. 

Thanks in advance. 

kuay