Question 1092470
I'll just do the first one:

 <pre>
2 | 1   -b      4   -20
  |<u>      2   4-2b   16-4b</u> 
    1   2-b  8-2b   -4-4b

The remainder is -4-4b and it must equal to -2,
so we set the remainder equal to -2:

                -4-4b = -2
                +4      +4
                ----------
                  -4b = 2

                  {{{(-4b)/(-4)}}}{{{""=""}}}{{{2/(-4)}}}
                    b = {{{-1/2}}}

Edwin</pre>