12.3: Division of Polynomials
We will begin with a property that is the converse of the Adding Fractions Property presented in Chapter 2.
For all real numbers
This property allows you to separate the numerator into its individual fractions. This property is used when dividing a polynomial by a monomial.
Example: Simplify
Solution: Using the property above, separate the polynomial into its individual fractions.
Example 1: Simplify
Solution: Separate the trinomial into its individual fractions and reduce.
Polynomials can also be divided by binomials. However, instead of separating into its individual fractions, we use a process called long division.
Example: Simplify
Solution: When we perform division, the expression in the numerator is called the dividend and the expression in the denominator is called the divisor.
To start the division we rewrite the problem in the following form.
Start by dividing the first term in the dividend by the first term in the divisor
Next, multiply the
Now subtract
Now, bring down 5, the next term in the dividend.
Repeat the process. First divide the first term of
Multiply 1 by the divisor
Subtract
Since there are no more terms from the dividend to bring down, we are done.
The answer is
Multimedia Link: For more help with using long division to simplify rational expressions, visit this http://www.purplemath.com/modules/polydiv2.htm  website or watch this CK12 Basic Algebra: 6 7 Polynomial long division with Mr. Nystrom
 YouTube video.
Practice Set
Sample explanations for some of the practice exercises below are available by viewing the following video. Note that there is not always a match between the number of the practice exercise in the video and the number of the practice exercise listed in the following exercise set. However, the practice exercise is the same in both. CK12 Basic Algebra: Polynomial Division (12:09)
Divide the following polynomials.

2x+42 
x−4x 
5x−355x 
x2+2x−5x 
4x2+12x−36−4x 
2x2+10x+72x2 
x3−x−2x2 
5x4−93x 
x3−12x2+3x−412x2 
3−6x+x3−9x3 
x2+3x+6x+1 
x2−9x+6x−1 
x2+5x+4x+4 
x2−10x+25x−5 
x2−20x+12x−3 
3x2−x+5x−2 
9x2+2x−8x+4 
3x2−43x+1 
5x2+2x−92x−1 
x2−6x−125x+4 
x4−2x8x+24 
x3+14x−1
Mixed Review
 Boyle’s Law states that the pressure of a compressed gas varies inversely as its pressure. If the pressure of a 200pound gas is 16.75 psi, find the pressure if the amount of gas is 60 pounds.
 Is
5x3+x2−x−1+8 an example of a polynomial? Explain your answer.  Find the slope of the line perpendicular to \begin{align*}y=\frac{3}{4} x+5\end{align*}.
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 What is a problem with facetoface interviews? What do you think is a potential solution to this problem?
 Solve for \begin{align*}m: 4= \frac{\sqrt{m3}}{2}\end{align*}.