Division of polynomials
Division of polynomials. What means to divide one polynomial P by another Q ? It means to find polynomials M ( quotient ) and N ( remainder ), satisfying the two requirements:
  1).  An equality
  
   MQ + N = P
  
  takes place;
  
  2).  A degree of polynomial
  
   N
  
  is less than a degree of polynomial
  
   Q
  
  .
 
  Division of polynomials can be done by the  following scheme (
  
   long division
  
  ):
  
  
  
 
  
  1)  Divide the first  term 16
  
   a
  
  
   
    3
   
  
  of the dividend by the first term  4
  
   a
  
  
   
    2
   
  
  of the divisor;  the result 
 4
  
   a
  
  is the first term of the quotient.
  
  
  2)  Multiply the received term 4
  
   a
  
  by the divisor 4
  
   a
  
  
   
    2
   
  
  
   – a +
  
  2; write the result 16
  
   a
  
  
   
    3
   
  
  
   –
  
  4
  
   a
  
  
   
    2
   
  
  
   +
  
  8
  
   a
  
  under the dividend, one similar term under another.
  
  
  3)  Subtract terms of the result from  the corresponding terms of the dividend and move down the next by the order term 7 of the dividend; the remainder is 12
  
   a
  
  
   
    2
   
  
  
   –
  
  13
  
   a +
  
  7 .
  
  
  4)  Divide the first term 12
  
   a
  
  
   
    2
   
  
  of this expression  by the  first term 4
  
   a
  
  
   
    2
   
  
  of the divisor;  the result 3  is the second 
term of the quotient.
  
  
  5)  Multiply the received second term 3 by the divisor 4
  
   a
  
  
   
    2
   
  
  
   – a +
  
  2; write the result 
12
  
   a
  
  
   
    2
   
  
  
   –
  
  3
  
   a +
  
  6  again  under the dividend, one similar term under another.
  
  
  6)  Subtract terms of the result from the corresponding terms of the previous remainder 
and receive the second remainder:
  
  
   –
  
  
   
   
  
  
   10
   
    a
   
  
  
   
   
   
    +
   
   
   
  
  
   1. Its degree is less than the divisor degree,  therefore the division has been finished. The quotient is  4
   
    a +
   
   3,
   
   the remainder is
   
    –
   
  
  
  
  
   10
   
    a +
   
   1.