title: Symbloc expression vector into matrix form
body: <p>Suppose I have a symbolic expression vector like: <code>[-2*y+x-4,-5*y+x+13]</code>.
  How can I decompose it into two variables, say <code>A = [-2 -5; 1 1]</code> and <code>b = [-4;13]</code>?</p>
  
  <p>But this should be done dynamically for n number of variables and m entries of the row vector.</p>