Derive a simple Equation for Matrices

HI i am a beginner student in matlab.

I have a question regarding the particular picture shown. Can i simplify the equation to in terms of a and b for (a,b,c,d,e,g) to put in matrices. Or is there alternative to a simple matrices. Rather than having to input 7 equations into a matrix.

[Walter Roberson]

Think about

% a  b  c  d  e  f  g
  -1       1
  -1          1
    -1           1
    -3        4  1  1