title: Adding negative and positive binary?
body: <p>X = 01001001 and Y = 10101010<br/>
  <br/>
  If I want to add them together how do I do that? They are "Two's Complement"...
  I have tried a lots of things but I am not quite sure I am getting the right answer since there seems to be different type of rules.<br/>
  <br/>
  Just want to make sure it is correct:<br/>
   1. Add them as they are do not convert the negative<br/>
   2. Convert the negative number you get and that's the sum.<br/>
  <br/>
  f.eks<br/>
  01001001+10101010 = 11110011 => 00001100 => 1101 => -13<br/>
  <br/>
  Or? <br/>
   1. Convert the negative<br/>
   2. Add them together and convert the negative<br/>
  <br/>
  f.eks<br/>
  01001001+10101010 => 01001001 + 01010110 => 10011111 => 01100001 => -97 <br/>
  <br/>
  <br/>
  So basically what I want to do is to take: X-Y, and X+Y <br/>
  Can someone tell me how to do that?<br/>
  <br/>
  Some resource sites:
  <a href="http://www.cs.grinnell.edu/~rebelsky/Courses/CS152/97F/Readings/student-binary.html" rel="noreferrer">student-binary</a>
  <a href="http://celtickane.com/computers/cs_binary.php" rel="noreferrer">celtickane</a>
  <a href="http://www.swarthmore.edu/NatSci/echeeve1/Ref/BinaryMath/BinaryMath.html" rel="noreferrer">swarthmore</a></p>