title: Convert the following expression to product-of-sum (POS) form
body: <p>Convert the following expression to product-of-sum (POS) form:
  a.  AB + CD(AB̅ + CD)
  b.  AB(B̅C̅ + BD)  </p>
  
  <p>I'm trying to understand how you apply boolean algebra rules and convert these into product-of-sum form. </p>